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MathsAges 10-12

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 10-12

Area of a triangle

Take your time. Show your thinking.

  1. 1. A triangle has base 20 cm and perpendicular height 9 cm. Find its area.

    20 cm · 9 cm · Area of a triangle

  2. 2. A triangle has base 26 cm and perpendicular height 5 cm. Find its area.

    26 cm · 5 cm · Area of a triangle

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

    4 cm · 9 cm · Area of a triangle

  4. 4. A triangle has base 22 cm and perpendicular height 5 cm. Find its area.

    22 cm · 5 cm · Area of a triangle

  5. 5. A triangle has base 26 cm and perpendicular height 3 cm. Find its area.

    26 cm · 3 cm · Area of a triangle

  6. 6. A triangle has base 18 cm and perpendicular height 17 cm. Find its area.

    18 cm · 17 cm · Area of a triangle

  7. 7. A triangle has base 18 cm and perpendicular height 4 cm. Find its area.

    18 cm · 4 cm · Area of a triangle

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

    4 cm · 2 cm · Area of a triangle

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

    4 cm · 12 cm · Area of a triangle

  10. 10. A triangle has base 30 cm and perpendicular height 13 cm. Find its area.

    30 cm · 13 cm · Area of a triangle

  11. 11. A triangle has base 12 cm and perpendicular height 16 cm. Find its area.

    12 cm · 16 cm · Area of a triangle

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

    14 cm · 17 cm · Area of a triangle
12 questions · Seed 50 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12

Area of a triangle

Answers and reasoning. Review before teaching.

  1. 1. A triangle has base 20 cm and perpendicular height 9 cm. Find its area.

    90 cm²

    Area = ½ × base × height = ½ × 20 × 9 = 90 cm².

  2. 2. A triangle has base 26 cm and perpendicular height 5 cm. Find its area.

    65 cm²

    Area = ½ × base × height = ½ × 26 × 5 = 65 cm².

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

    18 cm²

    Area = ½ × base × height = ½ × 4 × 9 = 18 cm².

  4. 4. A triangle has base 22 cm and perpendicular height 5 cm. Find its area.

    55 cm²

    Area = ½ × base × height = ½ × 22 × 5 = 55 cm².

  5. 5. A triangle has base 26 cm and perpendicular height 3 cm. Find its area.

    39 cm²

    Area = ½ × base × height = ½ × 26 × 3 = 39 cm².

  6. 6. A triangle has base 18 cm and perpendicular height 17 cm. Find its area.

    153 cm²

    Area = ½ × base × height = ½ × 18 × 17 = 153 cm².

  7. 7. A triangle has base 18 cm and perpendicular height 4 cm. Find its area.

    36 cm²

    Area = ½ × base × height = ½ × 18 × 4 = 36 cm².

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

    4 cm²

    Area = ½ × base × height = ½ × 4 × 2 = 4 cm².

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

    24 cm²

    Area = ½ × base × height = ½ × 4 × 12 = 24 cm².

  10. 10. A triangle has base 30 cm and perpendicular height 13 cm. Find its area.

    195 cm²

    Area = ½ × base × height = ½ × 30 × 13 = 195 cm².

  11. 11. A triangle has base 12 cm and perpendicular height 16 cm. Find its area.

    96 cm²

    Area = ½ × base × height = ½ × 12 × 16 = 96 cm².

  12. 12. 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.

12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Area of a triangle

Take your time. Show your thinking.

  1. 1. A triangle has base 20 cm and perpendicular height 9 cm. Find its area.

    20 cm · 9 cm · Area of a triangle

  2. 2. A triangle has base 26 cm and perpendicular height 5 cm. Find its area.

    26 cm · 5 cm · Area of a triangle

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

    4 cm · 9 cm · Area of a triangle

  4. 4. A triangle has base 22 cm and perpendicular height 5 cm. Find its area.

    22 cm · 5 cm · Area of a triangle

  5. 5. A triangle has base 26 cm and perpendicular height 3 cm. Find its area.

    26 cm · 3 cm · Area of a triangle

  6. 6. A triangle has base 18 cm and perpendicular height 17 cm. Find its area.

    18 cm · 17 cm · Area of a triangle

  7. 7. A triangle has base 18 cm and perpendicular height 4 cm. Find its area.

    18 cm · 4 cm · Area of a triangle

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

    4 cm · 2 cm · Area of a triangle

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

    4 cm · 12 cm · Area of a triangle

  10. 10. A triangle has base 30 cm and perpendicular height 13 cm. Find its area.

    30 cm · 13 cm · Area of a triangle

  11. 11. A triangle has base 12 cm and perpendicular height 16 cm. Find its area.

    12 cm · 16 cm · Area of a triangle

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

    14 cm · 17 cm · Area of a triangle
12 questions · Seed 50 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Area of a triangle

Answers and reasoning. Review before teaching.

  1. 1. A triangle has base 20 cm and perpendicular height 9 cm. Find its area.

    90 cm²

    Area = ½ × base × height = ½ × 20 × 9 = 90 cm².

  2. 2. A triangle has base 26 cm and perpendicular height 5 cm. Find its area.

    65 cm²

    Area = ½ × base × height = ½ × 26 × 5 = 65 cm².

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

    18 cm²

    Area = ½ × base × height = ½ × 4 × 9 = 18 cm².

  4. 4. A triangle has base 22 cm and perpendicular height 5 cm. Find its area.

    55 cm²

    Area = ½ × base × height = ½ × 22 × 5 = 55 cm².

  5. 5. A triangle has base 26 cm and perpendicular height 3 cm. Find its area.

    39 cm²

    Area = ½ × base × height = ½ × 26 × 3 = 39 cm².

  6. 6. A triangle has base 18 cm and perpendicular height 17 cm. Find its area.

    153 cm²

    Area = ½ × base × height = ½ × 18 × 17 = 153 cm².

  7. 7. A triangle has base 18 cm and perpendicular height 4 cm. Find its area.

    36 cm²

    Area = ½ × base × height = ½ × 18 × 4 = 36 cm².

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

    4 cm²

    Area = ½ × base × height = ½ × 4 × 2 = 4 cm².

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

    24 cm²

    Area = ½ × base × height = ½ × 4 × 12 = 24 cm².

  10. 10. A triangle has base 30 cm and perpendicular height 13 cm. Find its area.

    195 cm²

    Area = ½ × base × height = ½ × 30 × 13 = 195 cm².

  11. 11. A triangle has base 12 cm and perpendicular height 16 cm. Find its area.

    96 cm²

    Area = ½ × base × height = ½ × 12 × 16 = 96 cm².

  12. 12. 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.

12 questions · Seed 50 · Age guidance, not curriculum certification