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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 18 cm and perpendicular height 2 cm. Find its area.

    18 cm · 2 cm · Area of a triangle

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

    12 cm · 5 cm · Area of a triangle

  3. 3. A triangle has base 4 cm and perpendicular height 16 cm. Find its area.

    4 cm · 16 cm · Area of a triangle

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

    10 cm · 10 cm · Area of a triangle

  5. 5. A triangle has base 20 cm and perpendicular height 18 cm. Find its area.

    20 cm · 18 cm · Area of a triangle

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

    18 cm · 7 cm · Area of a triangle

  7. 7. A triangle has base 26 cm and perpendicular height 16 cm. Find its area.

    26 cm · 16 cm · Area of a triangle

  8. 8. A triangle has base 18 cm and perpendicular height 14 cm. Find its area.

    18 cm · 14 cm · Area of a triangle

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

    18 cm · 18 cm · Area of a triangle

  10. 10. A triangle has base 8 cm and perpendicular height 3 cm. Find its area.

    8 cm · 3 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 14 cm and perpendicular height 8 cm. Find its area.

    14 cm · 8 cm · Area of a triangle
12 questions · Seed 48 · 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 18 cm and perpendicular height 2 cm. Find its area.

    18 cm²

    Area = ½ × base × height = ½ × 18 × 2 = 18 cm².

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

    30 cm²

    Area = ½ × base × height = ½ × 12 × 5 = 30 cm².

  3. 3. A triangle has base 4 cm and perpendicular height 16 cm. Find its area.

    32 cm²

    Area = ½ × base × height = ½ × 4 × 16 = 32 cm².

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

    50 cm²

    Area = ½ × base × height = ½ × 10 × 10 = 50 cm².

  5. 5. A triangle has base 20 cm and perpendicular height 18 cm. Find its area.

    180 cm²

    Area = ½ × base × height = ½ × 20 × 18 = 180 cm².

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

    63 cm²

    Area = ½ × base × height = ½ × 18 × 7 = 63 cm².

  7. 7. A triangle has base 26 cm and perpendicular height 16 cm. Find its area.

    208 cm²

    Area = ½ × base × height = ½ × 26 × 16 = 208 cm².

  8. 8. A triangle has base 18 cm and perpendicular height 14 cm. Find its area.

    126 cm²

    Area = ½ × base × height = ½ × 18 × 14 = 126 cm².

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

    162 cm²

    Area = ½ × base × height = ½ × 18 × 18 = 162 cm².

  10. 10. A triangle has base 8 cm and perpendicular height 3 cm. Find its area.

    12 cm²

    Area = ½ × base × height = ½ × 8 × 3 = 12 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 14 cm and perpendicular height 8 cm. Find its area.

    56 cm²

    Area = ½ × base × height = ½ × 14 × 8 = 56 cm².

12 questions · Seed 48 · 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 18 cm and perpendicular height 2 cm. Find its area.

    18 cm · 2 cm · Area of a triangle

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

    12 cm · 5 cm · Area of a triangle

  3. 3. A triangle has base 4 cm and perpendicular height 16 cm. Find its area.

    4 cm · 16 cm · Area of a triangle

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

    10 cm · 10 cm · Area of a triangle

  5. 5. A triangle has base 20 cm and perpendicular height 18 cm. Find its area.

    20 cm · 18 cm · Area of a triangle

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

    18 cm · 7 cm · Area of a triangle

  7. 7. A triangle has base 26 cm and perpendicular height 16 cm. Find its area.

    26 cm · 16 cm · Area of a triangle

  8. 8. A triangle has base 18 cm and perpendicular height 14 cm. Find its area.

    18 cm · 14 cm · Area of a triangle

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

    18 cm · 18 cm · Area of a triangle

  10. 10. A triangle has base 8 cm and perpendicular height 3 cm. Find its area.

    8 cm · 3 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 14 cm and perpendicular height 8 cm. Find its area.

    14 cm · 8 cm · Area of a triangle
12 questions · Seed 48 · 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 18 cm and perpendicular height 2 cm. Find its area.

    18 cm²

    Area = ½ × base × height = ½ × 18 × 2 = 18 cm².

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

    30 cm²

    Area = ½ × base × height = ½ × 12 × 5 = 30 cm².

  3. 3. A triangle has base 4 cm and perpendicular height 16 cm. Find its area.

    32 cm²

    Area = ½ × base × height = ½ × 4 × 16 = 32 cm².

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

    50 cm²

    Area = ½ × base × height = ½ × 10 × 10 = 50 cm².

  5. 5. A triangle has base 20 cm and perpendicular height 18 cm. Find its area.

    180 cm²

    Area = ½ × base × height = ½ × 20 × 18 = 180 cm².

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

    63 cm²

    Area = ½ × base × height = ½ × 18 × 7 = 63 cm².

  7. 7. A triangle has base 26 cm and perpendicular height 16 cm. Find its area.

    208 cm²

    Area = ½ × base × height = ½ × 26 × 16 = 208 cm².

  8. 8. A triangle has base 18 cm and perpendicular height 14 cm. Find its area.

    126 cm²

    Area = ½ × base × height = ½ × 18 × 14 = 126 cm².

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

    162 cm²

    Area = ½ × base × height = ½ × 18 × 18 = 162 cm².

  10. 10. A triangle has base 8 cm and perpendicular height 3 cm. Find its area.

    12 cm²

    Area = ½ × base × height = ½ × 8 × 3 = 12 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 14 cm and perpendicular height 8 cm. Find its area.

    56 cm²

    Area = ½ × base × height = ½ × 14 × 8 = 56 cm².

12 questions · Seed 48 · Age guidance, not curriculum certification