{
  "title": "Triangle Properties - Grade 7 ICSE",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "easy",
      "question": "How many sides does a triangle have? 🔺",
      "options": { "A": "2", "B": "3", "C": "4", "D": "5" },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "easy",
      "question": "The sum of angles in a triangle is: 📐",
      "options": { "A": "90°", "B": "180°", "C": "270°", "D": "360°" },
      "correct_answer": "B"
    },
    {
      "id": 3,
      "difficulty": "easy",
      "question": "A triangle with all sides equal is called: 🔺",
      "options": {
        "A": "Isosceles",
        "B": "Scalene",
        "C": "Equilateral",
        "D": "Right"
      },
      "correct_answer": "C"
    },
    {
      "id": 4,
      "difficulty": "easy",
      "question": "A triangle with one angle 90° is called: ⬜",
      "options": {
        "A": "Acute",
        "B": "Obtuse",
        "C": "Right",
        "D": "Equilateral"
      },
      "correct_answer": "C"
    },
    {
      "id": 5,
      "difficulty": "easy",
      "question": "If two sides of a triangle are equal, it is: 🔺",
      "options": {
        "A": "Scalene",
        "B": "Isosceles",
        "C": "Equilateral",
        "D": "Right"
      },
      "correct_answer": "B"
    },
    {
      "id": 6,
      "difficulty": "easy",
      "question": "All angles in an equilateral triangle are: 📏",
      "options": { "A": "45°", "B": "60°", "C": "90°", "D": "120°" },
      "correct_answer": "B"
    },
    {
      "id": 7,
      "difficulty": "easy",
      "question": "The longest side of a right triangle is called: 🏔️",
      "options": { "A": "Base", "B": "Height", "C": "Hypotenuse", "D": "Leg" },
      "correct_answer": "C"
    },
    {
      "id": 8,
      "difficulty": "easy",
      "question": "If one angle of a triangle is 110°, the triangle is: 📐",
      "options": {
        "A": "Acute",
        "B": "Right",
        "C": "Obtuse",
        "D": "Equilateral"
      },
      "correct_answer": "C"
    },
    {
      "id": 9,
      "difficulty": "easy",
      "question": "In a triangle, the side opposite the largest angle is: 📍",
      "options": {
        "A": "Smallest",
        "B": "Largest",
        "C": "Equal",
        "D": "Medium"
      },
      "correct_answer": "B"
    },
    {
      "id": 10,
      "difficulty": "easy",
      "question": "A triangle with all angles less than 90° is: 🔺",
      "options": {
        "A": "Acute",
        "B": "Obtuse",
        "C": "Right",
        "D": "Equilateral"
      },
      "correct_answer": "A"
    },
    {
      "id": 11,
      "difficulty": "easy",
      "question": "The sum of any two sides of a triangle is ______ the third side. ➕",
      "options": {
        "A": "Less than",
        "B": "Greater than",
        "C": "Equal to",
        "D": "Half of"
      },
      "correct_answer": "B"
    },
    {
      "id": 12,
      "difficulty": "easy",
      "question": "In ΔABC, if ∠A = 50°, ∠B = 60°, then ∠C = ? 🔢",
      "options": { "A": "50°", "B": "60°", "C": "70°", "D": "80°" },
      "correct_answer": "C"
    },
    {
      "id": 13,
      "difficulty": "easy",
      "question": "How many altitudes does a triangle have? 🏔️",
      "options": { "A": "1", "B": "2", "C": "3", "D": "4" },
      "correct_answer": "C"
    },
    {
      "id": 14,
      "difficulty": "easy",
      "question": "The point where all medians meet is called: 📍",
      "options": {
        "A": "Centroid",
        "B": "Circumcenter",
        "C": "Incenter",
        "D": "Orthocenter"
      },
      "correct_answer": "A"
    },
    {
      "id": 15,
      "difficulty": "easy",
      "question": "In a right triangle, the two acute angles are: ➕",
      "options": {
        "A": "Supplementary",
        "B": "Complementary",
        "C": "Equal",
        "D": "Vertical"
      },
      "correct_answer": "B"
    },
    {
      "id": 16,
      "difficulty": "easy",
      "question": "If two angles of a triangle are 45° and 45°, the triangle is: 🔺",
      "options": {
        "A": "Scalene",
        "B": "Isosceles right",
        "C": "Equilateral",
        "D": "Obtuse"
      },
      "correct_answer": "B"
    },
    {
      "id": 17,
      "difficulty": "easy",
      "question": "The perimeter of a triangle is the sum of its: 📏",
      "options": {
        "A": "Angles",
        "B": "Sides",
        "C": "Heights",
        "D": "Medians"
      },
      "correct_answer": "B"
    },
    {
      "id": 18,
      "difficulty": "easy",
      "question": "An exterior angle of a triangle equals the sum of: 🔄",
      "options": {
        "A": "All interior angles",
        "B": "Two interior opposite angles",
        "C": "Two exterior angles",
        "D": "Three sides"
      },
      "correct_answer": "B"
    },
    {
      "id": 19,
      "difficulty": "easy",
      "question": "Which triangle has no equal sides? 🔺",
      "options": {
        "A": "Equilateral",
        "B": "Isosceles",
        "C": "Scalene",
        "D": "Right"
      },
      "correct_answer": "C"
    },
    {
      "id": 20,
      "difficulty": "easy",
      "question": "In an isosceles triangle, angles opposite equal sides are: ⚖️",
      "options": {
        "A": "Equal",
        "B": "Different",
        "C": "Right angles",
        "D": "Supplementary"
      },
      "correct_answer": "A"
    },
    {
      "id": 21,
      "difficulty": "medium",
      "question": "In ΔABC, if ∠A = 60°, ∠B = 70°, find the exterior angle at C. 🔄",
      "options": { "A": "50°", "B": "110°", "C": "130°", "D": "310°" },
      "correct_answer": "C"
    },
    {
      "id": 22,
      "difficulty": "medium",
      "question": "If the angles of a triangle are in ratio 2:3:5, find the largest angle. 📊",
      "options": { "A": "36°", "B": "54°", "C": "72°", "D": "90°" },
      "correct_answer": "D"
    },
    {
      "id": 23,
      "difficulty": "medium",
      "question": "Can a triangle have sides 3cm, 4cm, 8cm? 🤔",
      "options": {
        "A": "Yes",
        "B": "No",
        "C": "Only if right triangle",
        "D": "Only if obtuse"
      },
      "correct_answer": "B"
    },
    {
      "id": 24,
      "difficulty": "medium",
      "question": "In a right triangle, if one acute angle is 35°, the other is: 📐",
      "options": { "A": "35°", "B": "55°", "C": "65°", "D": "145°" },
      "correct_answer": "B"
    },
    {
      "id": 25,
      "difficulty": "medium",
      "question": "The angles of a triangle are (x-20)°, (x+10)°, and (x/2)°. Find x. 🧮",
      "options": { "A": "60", "B": "76", "C": "80", "D": "90" },
      "correct_answer": "B"
    },
    {
      "id": 26,
      "difficulty": "medium",
      "question": "In an isosceles triangle, the vertical angle is 40°. Find each base angle. 🔺",
      "options": { "A": "40°", "B": "70°", "C": "80°", "D": "140°" },
      "correct_answer": "B"
    },
    {
      "id": 27,
      "difficulty": "medium",
      "question": "If one angle of an isosceles triangle is 100°, find the other two angles. 📏",
      "options": {
        "A": "40°, 40°",
        "B": "50°, 30°",
        "C": "60°, 20°",
        "D": "80°, 0°"
      },
      "correct_answer": "A"
    },
    {
      "id": 28,
      "difficulty": "medium",
      "question": "In ΔABC, AB=AC and ∠B=50°. Find ∠A. 🔍",
      "options": { "A": "50°", "B": "60°", "C": "80°", "D": "100°" },
      "correct_answer": "C"
    },
    {
      "id": 29,
      "difficulty": "medium",
      "question": "The exterior angle at vertex A of ΔABC is 120°. If ∠B=50°, find ∠C. 🔄",
      "options": { "A": "50°", "B": "60°", "C": "70°", "D": "80°" },
      "correct_answer": "C"
    },
    {
      "id": 30,
      "difficulty": "medium",
      "question": "Can a triangle have two right angles? 🚫",
      "options": {
        "A": "Yes",
        "B": "No",
        "C": "Only in special case",
        "D": "Only in equilateral"
      },
      "correct_answer": "B"
    },
    {
      "id": 31,
      "difficulty": "medium",
      "question": "In a triangle, if ∠A=∠B=45°, what type of triangle is it? 🔺",
      "options": {
        "A": "Scalene right",
        "B": "Isosceles right",
        "C": "Equilateral",
        "D": "Obtuse"
      },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "medium",
      "question": "The sides of a triangle are 7cm, 10cm, and 12cm. Is it a right triangle? 📐",
      "options": {
        "A": "Yes",
        "B": "No",
        "C": "Cannot say",
        "D": "Only if 7²+10²=12²"
      },
      "correct_answer": "B"
    },
    {
      "id": 33,
      "difficulty": "medium",
      "question": "If the base angles of an isosceles triangle are each 55°, find the vertical angle. 🧩",
      "options": { "A": "55°", "B": "70°", "C": "80°", "D": "90°" },
      "correct_answer": "B"
    },
    {
      "id": 34,
      "difficulty": "medium",
      "question": "In ΔPQR, ∠P=60°, ∠Q=80°. Find the exterior angle at R. 🔄",
      "options": { "A": "40°", "B": "100°", "C": "140°", "D": "320°" },
      "correct_answer": "C"
    },
    {
      "id": 35,
      "difficulty": "medium",
      "question": "Which set can be sides of a triangle? 📏",
      "options": { "A": "2,3,5", "B": "3,4,5", "C": "1,2,4", "D": "5,10,20" },
      "correct_answer": "B"
    },
    {
      "id": 36,
      "difficulty": "medium",
      "question": "In an equilateral triangle, each exterior angle is: 🔄",
      "options": { "A": "60°", "B": "120°", "C": "180°", "D": "240°" },
      "correct_answer": "B"
    },
    {
      "id": 37,
      "difficulty": "medium",
      "question": "If two angles of a triangle are 30° and 60°, the triangle is: 📐",
      "options": {
        "A": "Acute",
        "B": "Right",
        "C": "Obtuse",
        "D": "Equilateral"
      },
      "correct_answer": "B"
    },
    {
      "id": 38,
      "difficulty": "medium",
      "question": "In ΔABC, if ∠A=70° and ∠B=60°, which side is longest? 📍",
      "options": { "A": "AB", "B": "BC", "C": "CA", "D": "All equal" },
      "correct_answer": "B"
    },
    {
      "id": 39,
      "difficulty": "medium",
      "question": "The sum of two angles of a triangle is 110°. Find the third angle. ➕",
      "options": { "A": "50°", "B": "70°", "C": "110°", "D": "250°" },
      "correct_answer": "B"
    },
    {
      "id": 40,
      "difficulty": "medium",
      "question": "In a right triangle, the hypotenuse is 13cm and one leg is 5cm. Find the other leg. 📏",
      "options": { "A": "8 cm", "B": "10 cm", "C": "12 cm", "D": "14 cm" },
      "correct_answer": "C"
    },
    {
      "id": 41,
      "difficulty": "hard",
      "question": "In ΔABC, ∠A=50°. The bisectors of ∠B and ∠C meet at O. Find ∠BOC. ✂️",
      "options": { "A": "115°", "B": "125°", "C": "130°", "D": "140°" },
      "correct_answer": "A"
    },
    {
      "id": 42,
      "difficulty": "hard",
      "question": "If the angles of a triangle are in ratio 1:2:3, find the ratio of sides opposite these angles. 📊",
      "options": { "A": "1:2:3", "B": "1:√3:2", "C": "1:√2:√3", "D": "3:4:5" },
      "correct_answer": "B"
    },
    {
      "id": 43,
      "difficulty": "hard",
      "question": "In an isosceles triangle, the altitude from the vertex bisects the base. True or False? ⚖️",
      "options": {
        "A": "True",
        "B": "False",
        "C": "Sometimes true",
        "D": "Only for right triangles"
      },
      "correct_answer": "A"
    },
    {
      "id": 44,
      "difficulty": "hard",
      "question": "The sides of a triangle are x, x+1, and x+2. If it's a right triangle, find x. 🔺",
      "options": { "A": "1", "B": "3", "C": "5", "D": "7" },
      "correct_answer": "B"
    },
    {
      "id": 45,
      "difficulty": "hard",
      "question": "In ΔABC, AB=AC. If exterior angle at A is 140°, find ∠B. 🔄",
      "options": { "A": "40°", "B": "70°", "C": "80°", "D": "110°" },
      "correct_answer": "B"
    },
    {
      "id": 46,
      "difficulty": "hard",
      "question": "The medians of an equilateral triangle are equal. True or False? 📏",
      "options": {
        "A": "True",
        "B": "False",
        "C": "Sometimes true",
        "D": "Only for right triangles"
      },
      "correct_answer": "A"
    },
    {
      "id": 47,
      "difficulty": "hard",
      "question": "In a triangle, if one side is doubled and another side is halved, can it still be a triangle? 🤔",
      "options": {
        "A": "Always",
        "B": "Never",
        "C": "Sometimes",
        "D": "Only if third side is changed"
      },
      "correct_answer": "C"
    },
    {
      "id": 48,
      "difficulty": "hard",
      "question": "The sum of any two medians of a triangle is ______ the third median. ➕",
      "options": {
        "A": "Less than",
        "B": "Greater than",
        "C": "Equal to",
        "D": "Twice"
      },
      "correct_answer": "B"
    },
    {
      "id": 49,
      "difficulty": "hard",
      "question": "In ΔPQR, ∠P=2∠Q=3∠R. Find ∠Q. 🧮",
      "options": {
        "A": "30°",
        "B": "40°",
        "C": "54°",
        "D": "60°"
      },
      "correct_answer": "C"
    },
    {
      "id": 50,
      "difficulty": "hard",
      "question": "If the altitude from the vertex of an isosceles triangle is 8cm and base is 12cm, find the equal sides. 🏔️",
      "options": { "A": "10 cm", "B": "12 cm", "C": "13 cm", "D": "15 cm" },
      "correct_answer": "A"
    },
    {
      "id": 51,
      "difficulty": "hard",
      "question": "In a right triangle, the median to the hypotenuse is ______ the hypotenuse. 📐",
      "options": {
        "A": "Equal to",
        "B": "Half of",
        "C": "Twice",
        "D": "One-third of"
      },
      "correct_answer": "B"
    },
    {
      "id": 52,
      "difficulty": "hard",
      "question": "The exterior angles of a triangle taken in order are 110°, 120°, and 130°. Find the interior angles. 🔄",
      "options": {
        "A": "50°,60°,70°",
        "B": "60°,70°,50°",
        "C": "70°,60°,50°",
        "D": "80°,50°,50°"
      },
      "correct_answer": "C"
    },
    {
      "id": 53,
      "difficulty": "hard",
      "question": "In ΔABC, if ∠A+∠B=120° and ∠B+∠C=130°, find ∠C. 🔍",
      "options": {
        "A": "50°",
        "B": "60°",
        "C": "70°",
        "D": "80°"
      },
      "correct_answer": "B"
    },
    {
      "id": 54,
      "difficulty": "hard",
      "question": "Can a triangle have sides in ratio 1:2:3? 📏",
      "options": {
        "A": "Yes",
        "B": "No",
        "C": "Only if right triangle",
        "D": "Only if obtuse"
      },
      "correct_answer": "B"
    },
    {
      "id": 55,
      "difficulty": "hard",
      "question": "The difference between two sides of a triangle is ______ the third side. ➖",
      "options": {
        "A": "Less than",
        "B": "Greater than",
        "C": "Equal to",
        "D": "Half of"
      },
      "correct_answer": "A"
    },
    {
      "id": 56,
      "difficulty": "hard",
      "question": "In an equilateral triangle of side a, the altitude is: 🏔️",
      "options": { "A": "a/2", "B": "√3a/2", "C": "a√2", "D": "a/√2" },
      "correct_answer": "B"
    },
    {
      "id": 57,
      "difficulty": "hard",
      "question": "If the angles of a triangle are in arithmetic progression with common difference 20°, find the smallest angle. 📊",
      "options": { "A": "20°", "B": "40°", "C": "60°", "D": "80°" },
      "correct_answer": "B"
    },
    {
      "id": 58,
      "difficulty": "hard",
      "question": "In a triangle, the sum of two sides is 20cm and their difference is 4cm. If the third side is 12cm, is the triangle possible? 🤔",
      "options": {
        "A": "Yes",
        "B": "No",
        "C": "Only if right triangle",
        "D": "Only if obtuse"
      },
      "correct_answer": "A"
    },
    {
      "id": 59,
      "difficulty": "hard",
      "question": "The centroid divides each median in ratio: 📍",
      "options": { "A": "1:1", "B": "1:2", "C": "2:1", "D": "3:1" },
      "correct_answer": "C"
    },
    {
      "id": 60,
      "difficulty": "hard",
      "question": "In a right triangle, if one acute angle is twice the other, the hypotenuse is ______ times the smaller side. 🔢",
      "options": { "A": "√2", "B": "√3", "C": "2", "D": "√5" },
      "correct_answer": "C"
    }
  ]
}