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MathsAges 13-15

Area of a triangle

Calculate the area of a triangle from its base and perpendicular height using A = ½bh. Review suitability for your learners before teaching.

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Age band:Ages 10-12Ages 13-15

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Worksheet StudioPractice pack · Ages 13-15

Area of a triangle

Take your time. Show your thinking.

  1. 1. A triangle has base 20 cm and perpendicular height 4 cm. Find its area.

    20 cm · 4 cm · Area of a triangle

  2. 2. A triangle has base 20 cm and perpendicular height 15 cm. Find its area.

    20 cm · 15 cm · Area of a triangle

  3. 3. A triangle has base 14 cm and perpendicular height 4 cm. Find its area.

    14 cm · 4 cm · Area of a triangle

  4. 4. A triangle has base 14 cm and perpendicular height 17 cm. Find its area.

    14 cm · 17 cm · Area of a triangle

  5. 5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.

    28 cm · 11 cm · Area of a triangle

  6. 6. A triangle has base 24 cm and perpendicular height 15 cm. Find its area.

    24 cm · 15 cm · Area of a triangle

  7. 7. A triangle has base 10 cm and perpendicular height 5 cm. Find its area.

    10 cm · 5 cm · Area of a triangle

  8. 8. A triangle has base 6 cm and perpendicular height 10 cm. Find its area.

    6 cm · 10 cm · Area of a triangle

  9. 9. A triangle has base 26 cm and perpendicular height 4 cm. Find its area.

    26 cm · 4 cm · Area of a triangle

  10. 10. A triangle has base 12 cm and perpendicular height 7 cm. Find its area.

    12 cm · 7 cm · Area of a triangle

  11. 11. A triangle has base 32 cm and perpendicular height 8 cm. Find its area.

    32 cm · 8 cm · Area of a triangle

  12. 12. A triangle has base 20 cm and perpendicular height 17 cm. Find its area.

    20 cm · 17 cm · Area of a triangle
12 questions · Seed 59 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 13-15

Area of a triangle

Answers and reasoning. Review before teaching.

  1. 1. A triangle has base 20 cm and perpendicular height 4 cm. Find its area.

    40 cm²

    Area = ½ × base × height = ½ × 20 × 4 = 40 cm².

  2. 2. A triangle has base 20 cm and perpendicular height 15 cm. Find its area.

    150 cm²

    Area = ½ × base × height = ½ × 20 × 15 = 150 cm².

  3. 3. A triangle has base 14 cm and perpendicular height 4 cm. Find its area.

    28 cm²

    Area = ½ × base × height = ½ × 14 × 4 = 28 cm².

  4. 4. A triangle has base 14 cm and perpendicular height 17 cm. Find its area.

    119 cm²

    Area = ½ × base × height = ½ × 14 × 17 = 119 cm².

  5. 5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.

    154 cm²

    Area = ½ × base × height = ½ × 28 × 11 = 154 cm².

  6. 6. A triangle has base 24 cm and perpendicular height 15 cm. Find its area.

    180 cm²

    Area = ½ × base × height = ½ × 24 × 15 = 180 cm².

  7. 7. A triangle has base 10 cm and perpendicular height 5 cm. Find its area.

    25 cm²

    Area = ½ × base × height = ½ × 10 × 5 = 25 cm².

  8. 8. A triangle has base 6 cm and perpendicular height 10 cm. Find its area.

    30 cm²

    Area = ½ × base × height = ½ × 6 × 10 = 30 cm².

  9. 9. A triangle has base 26 cm and perpendicular height 4 cm. Find its area.

    52 cm²

    Area = ½ × base × height = ½ × 26 × 4 = 52 cm².

  10. 10. A triangle has base 12 cm and perpendicular height 7 cm. Find its area.

    42 cm²

    Area = ½ × base × height = ½ × 12 × 7 = 42 cm².

  11. 11. A triangle has base 32 cm and perpendicular height 8 cm. Find its area.

    128 cm²

    Area = ½ × base × height = ½ × 32 × 8 = 128 cm².

  12. 12. A triangle has base 20 cm and perpendicular height 17 cm. Find its area.

    170 cm²

    Area = ½ × base × height = ½ × 20 × 17 = 170 cm².

12 questions · Seed 59 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 13-15

Area of a triangle

Take your time. Show your thinking.

  1. 1. A triangle has base 20 cm and perpendicular height 4 cm. Find its area.

    20 cm · 4 cm · Area of a triangle

  2. 2. A triangle has base 20 cm and perpendicular height 15 cm. Find its area.

    20 cm · 15 cm · Area of a triangle

  3. 3. A triangle has base 14 cm and perpendicular height 4 cm. Find its area.

    14 cm · 4 cm · Area of a triangle

  4. 4. A triangle has base 14 cm and perpendicular height 17 cm. Find its area.

    14 cm · 17 cm · Area of a triangle

  5. 5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.

    28 cm · 11 cm · Area of a triangle

  6. 6. A triangle has base 24 cm and perpendicular height 15 cm. Find its area.

    24 cm · 15 cm · Area of a triangle

  7. 7. A triangle has base 10 cm and perpendicular height 5 cm. Find its area.

    10 cm · 5 cm · Area of a triangle

  8. 8. A triangle has base 6 cm and perpendicular height 10 cm. Find its area.

    6 cm · 10 cm · Area of a triangle

  9. 9. A triangle has base 26 cm and perpendicular height 4 cm. Find its area.

    26 cm · 4 cm · Area of a triangle

  10. 10. A triangle has base 12 cm and perpendicular height 7 cm. Find its area.

    12 cm · 7 cm · Area of a triangle

  11. 11. A triangle has base 32 cm and perpendicular height 8 cm. Find its area.

    32 cm · 8 cm · Area of a triangle

  12. 12. A triangle has base 20 cm and perpendicular height 17 cm. Find its area.

    20 cm · 17 cm · Area of a triangle
12 questions · Seed 59 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 13-15

Area of a triangle

Answers and reasoning. Review before teaching.

  1. 1. A triangle has base 20 cm and perpendicular height 4 cm. Find its area.

    40 cm²

    Area = ½ × base × height = ½ × 20 × 4 = 40 cm².

  2. 2. A triangle has base 20 cm and perpendicular height 15 cm. Find its area.

    150 cm²

    Area = ½ × base × height = ½ × 20 × 15 = 150 cm².

  3. 3. A triangle has base 14 cm and perpendicular height 4 cm. Find its area.

    28 cm²

    Area = ½ × base × height = ½ × 14 × 4 = 28 cm².

  4. 4. A triangle has base 14 cm and perpendicular height 17 cm. Find its area.

    119 cm²

    Area = ½ × base × height = ½ × 14 × 17 = 119 cm².

  5. 5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.

    154 cm²

    Area = ½ × base × height = ½ × 28 × 11 = 154 cm².

  6. 6. A triangle has base 24 cm and perpendicular height 15 cm. Find its area.

    180 cm²

    Area = ½ × base × height = ½ × 24 × 15 = 180 cm².

  7. 7. A triangle has base 10 cm and perpendicular height 5 cm. Find its area.

    25 cm²

    Area = ½ × base × height = ½ × 10 × 5 = 25 cm².

  8. 8. A triangle has base 6 cm and perpendicular height 10 cm. Find its area.

    30 cm²

    Area = ½ × base × height = ½ × 6 × 10 = 30 cm².

  9. 9. A triangle has base 26 cm and perpendicular height 4 cm. Find its area.

    52 cm²

    Area = ½ × base × height = ½ × 26 × 4 = 52 cm².

  10. 10. A triangle has base 12 cm and perpendicular height 7 cm. Find its area.

    42 cm²

    Area = ½ × base × height = ½ × 12 × 7 = 42 cm².

  11. 11. A triangle has base 32 cm and perpendicular height 8 cm. Find its area.

    128 cm²

    Area = ½ × base × height = ½ × 32 × 8 = 128 cm².

  12. 12. A triangle has base 20 cm and perpendicular height 17 cm. Find its area.

    170 cm²

    Area = ½ × base × height = ½ × 20 × 17 = 170 cm².

12 questions · Seed 59 · Age guidance, not curriculum certification