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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 14 cm. Find its area.

    20 cm · 14 cm · Area of a triangle

  2. 2. A triangle has base 20 cm and perpendicular height 3 cm. Find its area.

    20 cm · 3 cm · Area of a triangle

  3. 3. A triangle has base 22 cm and perpendicular height 18 cm. Find its area.

    22 cm · 18 cm · Area of a triangle

  4. 4. A triangle has base 12 cm and perpendicular height 2 cm. Find its area.

    12 cm · 2 cm · Area of a triangle

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

    12 cm · 17 cm · Area of a triangle

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

    14 cm · 17 cm · Area of a triangle

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

    26 cm · 9 cm · Area of a triangle

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

    6 cm · 6 cm · Area of a triangle

  9. 9. A triangle has base 14 cm and perpendicular height 12 cm. Find its area.

    14 cm · 12 cm · Area of a triangle

  10. 10. A triangle has base 26 cm and perpendicular height 18 cm. Find its area.

    26 cm · 18 cm · Area of a triangle

  11. 11. A triangle has base 24 cm and perpendicular height 9 cm. Find its area.

    24 cm · 9 cm · Area of a triangle

  12. 12. A triangle has base 10 cm and perpendicular height 17 cm. Find its area.

    10 cm · 17 cm · Area of a triangle
12 questions · Seed 68 · 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 14 cm. Find its area.

    140 cm²

    Area = ½ × base × height = ½ × 20 × 14 = 140 cm².

  2. 2. A triangle has base 20 cm and perpendicular height 3 cm. Find its area.

    30 cm²

    Area = ½ × base × height = ½ × 20 × 3 = 30 cm².

  3. 3. A triangle has base 22 cm and perpendicular height 18 cm. Find its area.

    198 cm²

    Area = ½ × base × height = ½ × 22 × 18 = 198 cm².

  4. 4. A triangle has base 12 cm and perpendicular height 2 cm. Find its area.

    12 cm²

    Area = ½ × base × height = ½ × 12 × 2 = 12 cm².

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

    102 cm²

    Area = ½ × base × height = ½ × 12 × 17 = 102 cm².

  6. 6. 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.

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

    117 cm²

    Area = ½ × base × height = ½ × 26 × 9 = 117 cm².

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

    18 cm²

    Area = ½ × base × height = ½ × 6 × 6 = 18 cm².

  9. 9. A triangle has base 14 cm and perpendicular height 12 cm. Find its area.

    84 cm²

    Area = ½ × base × height = ½ × 14 × 12 = 84 cm².

  10. 10. A triangle has base 26 cm and perpendicular height 18 cm. Find its area.

    234 cm²

    Area = ½ × base × height = ½ × 26 × 18 = 234 cm².

  11. 11. A triangle has base 24 cm and perpendicular height 9 cm. Find its area.

    108 cm²

    Area = ½ × base × height = ½ × 24 × 9 = 108 cm².

  12. 12. A triangle has base 10 cm and perpendicular height 17 cm. Find its area.

    85 cm²

    Area = ½ × base × height = ½ × 10 × 17 = 85 cm².

12 questions · Seed 68 · 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 14 cm. Find its area.

    20 cm · 14 cm · Area of a triangle

  2. 2. A triangle has base 20 cm and perpendicular height 3 cm. Find its area.

    20 cm · 3 cm · Area of a triangle

  3. 3. A triangle has base 22 cm and perpendicular height 18 cm. Find its area.

    22 cm · 18 cm · Area of a triangle

  4. 4. A triangle has base 12 cm and perpendicular height 2 cm. Find its area.

    12 cm · 2 cm · Area of a triangle

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

    12 cm · 17 cm · Area of a triangle

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

    14 cm · 17 cm · Area of a triangle

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

    26 cm · 9 cm · Area of a triangle

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

    6 cm · 6 cm · Area of a triangle

  9. 9. A triangle has base 14 cm and perpendicular height 12 cm. Find its area.

    14 cm · 12 cm · Area of a triangle

  10. 10. A triangle has base 26 cm and perpendicular height 18 cm. Find its area.

    26 cm · 18 cm · Area of a triangle

  11. 11. A triangle has base 24 cm and perpendicular height 9 cm. Find its area.

    24 cm · 9 cm · Area of a triangle

  12. 12. A triangle has base 10 cm and perpendicular height 17 cm. Find its area.

    10 cm · 17 cm · Area of a triangle
12 questions · Seed 68 · 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 14 cm. Find its area.

    140 cm²

    Area = ½ × base × height = ½ × 20 × 14 = 140 cm².

  2. 2. A triangle has base 20 cm and perpendicular height 3 cm. Find its area.

    30 cm²

    Area = ½ × base × height = ½ × 20 × 3 = 30 cm².

  3. 3. A triangle has base 22 cm and perpendicular height 18 cm. Find its area.

    198 cm²

    Area = ½ × base × height = ½ × 22 × 18 = 198 cm².

  4. 4. A triangle has base 12 cm and perpendicular height 2 cm. Find its area.

    12 cm²

    Area = ½ × base × height = ½ × 12 × 2 = 12 cm².

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

    102 cm²

    Area = ½ × base × height = ½ × 12 × 17 = 102 cm².

  6. 6. 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.

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

    117 cm²

    Area = ½ × base × height = ½ × 26 × 9 = 117 cm².

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

    18 cm²

    Area = ½ × base × height = ½ × 6 × 6 = 18 cm².

  9. 9. A triangle has base 14 cm and perpendicular height 12 cm. Find its area.

    84 cm²

    Area = ½ × base × height = ½ × 14 × 12 = 84 cm².

  10. 10. A triangle has base 26 cm and perpendicular height 18 cm. Find its area.

    234 cm²

    Area = ½ × base × height = ½ × 26 × 18 = 234 cm².

  11. 11. A triangle has base 24 cm and perpendicular height 9 cm. Find its area.

    108 cm²

    Area = ½ × base × height = ½ × 24 × 9 = 108 cm².

  12. 12. A triangle has base 10 cm and perpendicular height 17 cm. Find its area.

    85 cm²

    Area = ½ × base × height = ½ × 10 × 17 = 85 cm².

12 questions · Seed 68 · Age guidance, not curriculum certification