{
  "title": "Area of Triangle - Grade 4 ICSE",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=6 cm, height=4 cm. Area = ?",
      "options": { "A": "10 cm²", "B": "12 cm²", "C": "14 cm²", "D": "16 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "easy",
      "question": "📐 Triangle: base=8 cm, height=5 cm. Area = ?",
      "options": { "A": "18 cm²", "B": "20 cm²", "C": "22 cm²", "D": "24 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 3,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=10 m, height=6 m. Area = ?",
      "options": { "A": "28 m²", "B": "30 m²", "C": "32 m²", "D": "36 m²" },
      "correct_answer": "B"
    },
    {
      "id": 4,
      "difficulty": "easy",
      "question": "📏 Triangle: base=12 cm, height=7 cm. Area = ?",
      "options": { "A": "38 cm²", "B": "40 cm²", "C": "42 cm²", "D": "44 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 5,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=9 cm, height=8 cm. Area = ?",
      "options": { "A": "34 cm²", "B": "36 cm²", "C": "38 cm²", "D": "40 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 6,
      "difficulty": "easy",
      "question": "📐 Triangle: base=14 m, height=5 m. Area = ?",
      "options": { "A": "32 m²", "B": "34 m²", "C": "35 m²", "D": "36 m²" },
      "correct_answer": "C"
    },
    {
      "id": 7,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=11 cm, height=4 cm. Area = ?",
      "options": { "A": "20 cm²", "B": "22 cm²", "C": "24 cm²", "D": "26 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 8,
      "difficulty": "easy",
      "question": "📏 Triangle: base=15 cm, height=6 cm. Area = ?",
      "options": { "A": "42 cm²", "B": "44 cm²", "C": "45 cm²", "D": "48 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 9,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=20 m, height=8 m. Area = ?",
      "options": { "A": "76 m²", "B": "78 m²", "C": "80 m²", "D": "82 m²" },
      "correct_answer": "C"
    },
    {
      "id": 10,
      "difficulty": "easy",
      "question": "📐 Triangle: base=18 cm, height=5 cm. Area = ?",
      "options": { "A": "42 cm²", "B": "44 cm²", "C": "45 cm²", "D": "48 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 11,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=16 cm, height=9 cm. Area = ?",
      "options": { "A": "68 cm²", "B": "70 cm²", "C": "72 cm²", "D": "74 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 12,
      "difficulty": "easy",
      "question": "📏 Triangle: base=24 m, height=7 m. Area = ?",
      "options": { "A": "80 m²", "B": "82 m²", "C": "84 m²", "D": "86 m²" },
      "correct_answer": "C"
    },
    {
      "id": 13,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=13 cm, height=10 cm. Area = ?",
      "options": { "A": "62 cm²", "B": "64 cm²", "C": "65 cm²", "D": "68 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 14,
      "difficulty": "easy",
      "question": "📐 Triangle: base=22 cm, height=4 cm. Area = ?",
      "options": { "A": "42 cm²", "B": "44 cm²", "C": "46 cm²", "D": "48 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 15,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=30 m, height=12 m. Area = ?",
      "options": { "A": "176 m²", "B": "180 m²", "C": "184 m²", "D": "188 m²" },
      "correct_answer": "B"
    },
    {
      "id": 16,
      "difficulty": "easy",
      "question": "📏 Triangle: base=17 cm, height=8 cm. Area = ?",
      "options": { "A": "66 cm²", "B": "68 cm²", "C": "70 cm²", "D": "72 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 17,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=25 cm, height=6 cm. Area = ?",
      "options": { "A": "72 cm²", "B": "74 cm²", "C": "75 cm²", "D": "78 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 18,
      "difficulty": "easy",
      "question": "📐 Triangle: base=21 m, height=8 m. Area = ?",
      "options": { "A": "82 m²", "B": "84 m²", "C": "86 m²", "D": "88 m²" },
      "correct_answer": "B"
    },
    {
      "id": 19,
      "difficulty": "easy",
      "question": "🔺 Triangle: base=19 cm, height=4 cm. Area = ?",
      "options": { "A": "36 cm²", "B": "38 cm²", "C": "40 cm²", "D": "42 cm²" },
      "correct_answer": "B"
    },
    {
      "id": 20,
      "difficulty": "easy",
      "question": "📏 Triangle: base=28 cm, height=5 cm. Area = ?",
      "options": { "A": "68 cm²", "B": "70 cm²", "C": "72 cm²", "D": "74 cm²" },
      "correct_answer": "B"
    },

    {
      "id": 21,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 24 cm², base = 8 cm. Height = ?",
      "options": { "A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm" },
      "correct_answer": "B"
    },
    {
      "id": 22,
      "difficulty": "medium",
      "question": "📐 Triangle area = 36 m², height = 9 m. Base = ?",
      "options": { "A": "6 m", "B": "7 m", "C": "8 m", "D": "9 m" },
      "correct_answer": "C"
    },
    {
      "id": 23,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 42 cm², height = 7 cm. Base = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 24,
      "difficulty": "medium",
      "question": "📏 Right triangle: legs 6 cm and 8 cm. Area = ?",
      "options": { "A": "20 cm²", "B": "22 cm²", "C": "24 cm²", "D": "26 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 25,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 54 cm², base = 12 cm. Height = ?",
      "options": { "A": "8 cm", "B": "8.5 cm", "C": "9 cm", "D": "9.5 cm" },
      "correct_answer": "C"
    },
    {
      "id": 26,
      "difficulty": "medium",
      "question": "📐 Triangle area = 60 m², height = 10 m. Base = ?",
      "options": { "A": "10 m", "B": "11 m", "C": "12 m", "D": "13 m" },
      "correct_answer": "C"
    },
    {
      "id": 27,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 48 cm², base = 16 cm. Height = ?",
      "options": { "A": "5 cm", "B": "5.5 cm", "C": "6 cm", "D": "6.5 cm" },
      "correct_answer": "C"
    },
    {
      "id": 28,
      "difficulty": "medium",
      "question": "📏 Right triangle: legs 9 cm and 12 cm. Area = ?",
      "options": { "A": "50 cm²", "B": "52 cm²", "C": "54 cm²", "D": "56 cm²" },
      "correct_answer": "C"
    },
    {
      "id": 29,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 72 m², base = 18 m. Height = ?",
      "options": { "A": "7 m", "B": "8 m", "C": "9 m", "D": "10 m" },
      "correct_answer": "B"
    },
    {
      "id": 30,
      "difficulty": "medium",
      "question": "📐 Triangle area = 84 cm², height = 14 cm. Base = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 31,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 96 cm², base = 24 cm. Height = ?",
      "options": { "A": "7 cm", "B": "8 cm", "C": "9 cm", "D": "10 cm" },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "medium",
      "question": "📏 Right triangle: legs 15 cm and 20 cm. Area = ?",
      "options": {
        "A": "140 cm²",
        "B": "145 cm²",
        "C": "150 cm²",
        "D": "155 cm²"
      },
      "correct_answer": "C"
    },
    {
      "id": 33,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 108 m², height = 12 m. Base = ?",
      "options": { "A": "16 m", "B": "17 m", "C": "18 m", "D": "19 m" },
      "correct_answer": "C"
    },
    {
      "id": 34,
      "difficulty": "medium",
      "question": "📐 Triangle area = 120 cm², base = 20 cm. Height = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 35,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 144 m², height = 16 m. Base = ?",
      "options": { "A": "16 m", "B": "17 m", "C": "18 m", "D": "19 m" },
      "correct_answer": "C"
    },
    {
      "id": 36,
      "difficulty": "medium",
      "question": "📏 Right triangle: area 30 cm², one leg = 6 cm. Other leg = ?",
      "options": { "A": "8 cm", "B": "9 cm", "C": "10 cm", "D": "12 cm" },
      "correct_answer": "C"
    },
    {
      "id": 37,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 150 cm², base = 25 cm. Height = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 38,
      "difficulty": "medium",
      "question": "📐 Triangle area = 168 m², height = 21 m. Base = ?",
      "options": { "A": "14 m", "B": "15 m", "C": "16 m", "D": "17 m" },
      "correct_answer": "C"
    },
    {
      "id": 39,
      "difficulty": "medium",
      "question": "🔺 Triangle area = 180 cm², base = 30 cm. Height = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 40,
      "difficulty": "medium",
      "question": "📏 Right triangle: legs 24 cm and 10 cm. Area = ?",
      "options": {
        "A": "110 cm²",
        "B": "115 cm²",
        "C": "120 cm²",
        "D": "125 cm²"
      },
      "correct_answer": "C"
    },

    {
      "id": 41,
      "difficulty": "hard",
      "question": "🔺 Triangle area = rectangle area 48 cm². If same base=12 cm, triangle height = ? times rectangle width",
      "options": { "A": "1", "B": "1.5", "C": "2", "D": "2.5" },
      "correct_answer": "C"
    },
    {
      "id": 42,
      "difficulty": "hard",
      "question": "📐 Triangle base increased by 20%, height decreased by 20%. Area change?",
      "options": { "A": "-2%", "B": "-4%", "C": "-6%", "D": "-8%" },
      "correct_answer": "B"
    },
    {
      "id": 43,
      "difficulty": "hard",
      "question": "🔺 Right triangle area = 96 cm². If one leg is 12 cm, hypotenuse = ?",
      "options": { "A": "18 cm", "B": "20 cm", "C": "22 cm", "D": "24 cm" },
      "correct_answer": "B"
    },
    {
      "id": 44,
      "difficulty": "hard",
      "question": "📏 Triangle area = ½ × rectangle area. Both same base=16 cm. Triangle height=12 cm. Rectangle width?",
      "options": {
        "A": "10 cm",
        "B": "11 cm",
        "C": "12 cm",
        "D": "14 cm"
      },
      "correct_answer": "C"
    },
    {
      "id": 45,
      "difficulty": "hard",
      "question": "🔺 Triangle area doubled when base doubled. What happened to height?",
      "options": {
        "A": "Same",
        "B": "Doubled",
        "C": "Halved",
        "D": "Can't say"
      },
      "correct_answer": "A"
    },
    {
      "id": 46,
      "difficulty": "hard",
      "question": "📐 Two triangles: same area 60 cm². One base=15 cm, height=8 cm. Other base=12 cm, height=?",
      "options": { "A": "9 cm", "B": "10 cm", "C": "11 cm", "D": "12 cm" },
      "correct_answer": "B"
    },
    {
      "id": 47,
      "difficulty": "hard",
      "question": "🔺 Triangle area = 108 cm². Base:height = 3:2. Base = ?",
      "options": { "A": "15 cm", "B": "16 cm", "C": "17 cm", "D": "18 cm" },
      "correct_answer": "D"
    },
    {
      "id": 48,
      "difficulty": "hard",
      "question": "📏 Right triangle legs in ratio 3:4, area=150 cm². Longer leg = ?",
      "options": { "A": "15 cm", "B": "16 cm", "C": "18 cm", "D": "20 cm" },
      "correct_answer": "D"
    },
    {
      "id": 49,
      "difficulty": "hard",
      "question": "🔺 Triangle area increased by 44% when base increased 20%. Height change?",
      "options": { "A": "+15%", "B": "+18%", "C": "+20%", "D": "+24%" },
      "correct_answer": "C"
    },
    {
      "id": 50,
      "difficulty": "hard",
      "question": "📐 Two triangles: areas ratio 4:9. If bases same, heights ratio?",
      "options": {
        "A": "2:3",
        "B": "3:4",
        "C": "4:9",
        "D": "9:16"
      },
      "correct_answer": "C"
    },
    {
      "id": 51,
      "difficulty": "hard",
      "question": "🔺 Triangle area = ½ × base × height. If base tripled, height halved, area becomes ___ times",
      "options": { "A": "1.5", "B": "2", "C": "2.5", "D": "3" },
      "correct_answer": "A"
    },
    {
      "id": 52,
      "difficulty": "hard",
      "question": "📏 Triangle area = 180 cm². Base decreased by 25%, height increased by 60%. New area?",
      "options": {
        "A": "198 cm²",
        "B": "207 cm²",
        "C": "216 cm²",
        "D": "225 cm²"
      },
      "correct_answer": "C"
    },
    {
      "id": 53,
      "difficulty": "hard",
      "question": "🔺 Right triangle area=84 cm². Legs differ by 5 cm. Shorter leg?",
      "options": {
        "A": "10.7 cm",
        "B": "11.2 cm",
        "C": "12.0 cm",
        "D": "13.0 cm"
      },
      "correct_answer": "A"
    },
    {
      "id": 54,
      "difficulty": "hard",
      "question": "📐 Triangle area = square area 64 cm². Triangle base=16 cm, height same as square side. Square side?",
      "options": { "A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm" },
      "correct_answer": "C"
    },
    {
      "id": 55,
      "difficulty": "hard",
      "question": "🔺 Two triangles: areas equal. One base=18 cm, height=10 cm. Other base=15 cm, height=?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 56,
      "difficulty": "hard",
      "question": "📏 Triangle area increased from 50 cm² to 72 cm² when height increased 20%. Base change?",
      "options": { "A": "+20%", "B": "+22%", "C": "+24%", "D": "+26%" },
      "correct_answer": "A"
    },
    {
      "id": 57,
      "difficulty": "hard",
      "question": "🔺 Triangle base:height = 5:3. Area=120 cm². Perimeter if it's right triangle?",
      "options": {
        "A": "50 cm",
        "B": "52 cm",
        "C": "54 cm",
        "D": "56 cm"
      },
      "correct_answer": "D"
    },
    {
      "id": 58,
      "difficulty": "hard",
      "question": "📐 Equilateral triangle area = 36√3 cm². Side = ?",
      "options": { "A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm" },
      "correct_answer": "C"
    },
    {
      "id": 59,
      "difficulty": "hard",
      "question": "🔺 Triangle area = ½ of parallelogram area. Same base=14 cm. Triangle height=12 cm. Parallelogram height?",
      "options": {
        "A": "10 cm",
        "B": "11 cm",
        "C": "12 cm",
        "D": "14 cm"
      },
      "correct_answer": "C"
    },
    {
      "id": 60,
      "difficulty": "hard",
      "question": "📏 Right triangle area=30 cm². One leg=5 cm. Hypotenuse = ?",
      "options": { "A": "11 cm", "B": "12 cm", "C": "13 cm", "D": "14 cm" },
      "correct_answer": "C"
    }
  ]
}