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 10-12 Ages 13-15

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Worksheet StudioPractice pack · Ages 10-12

Area of a triangle

Take your time. Show your thinking.

1. A triangle has base 28 cm and perpendicular height 14 cm. Find its area.
28 cm · 14 cm · Area of a triangle
2. A triangle has base 12 cm and perpendicular height 17 cm. Find its area.
12 cm · 17 cm · Area of a triangle
3. A triangle has base 26 cm and perpendicular height 10 cm. Find its area.
26 cm · 10 cm · Area of a triangle
4. A triangle has base 20 cm and perpendicular height 16 cm. Find its area.
20 cm · 16 cm · Area of a triangle
5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.
28 cm · 11 cm · Area of a triangle
6. A triangle has base 10 cm and perpendicular height 3 cm. Find its area.
10 cm · 3 cm · Area of a triangle
7. A triangle has base 8 cm and perpendicular height 13 cm. Find its area.
8 cm · 13 cm · Area of a triangle
8. A triangle has base 16 cm and perpendicular height 14 cm. Find its area.
16 cm · 14 cm · Area of a triangle
9. A triangle has base 6 cm and perpendicular height 13 cm. Find its area.
6 cm · 13 cm · Area of a triangle
10. A triangle has base 10 cm and perpendicular height 10 cm. Find its area.
10 cm · 10 cm · Area of a triangle
11. A triangle has base 16 cm and perpendicular height 18 cm. Find its area.
16 cm · 18 cm · Area of a triangle
12. A triangle has base 16 cm and perpendicular height 13 cm. Find its area.
16 cm · 13 cm · Area of a triangle

12 questions · Seed 44 · 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. A triangle has base 28 cm and perpendicular height 14 cm. Find its area.
196 cm²
Area = ½ × base × height = ½ × 28 × 14 = 196 cm².
2. 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.
3. A triangle has base 26 cm and perpendicular height 10 cm. Find its area.
130 cm²
Area = ½ × base × height = ½ × 26 × 10 = 130 cm².
4. A triangle has base 20 cm and perpendicular height 16 cm. Find its area.
160 cm²
Area = ½ × base × height = ½ × 20 × 16 = 160 cm².
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. A triangle has base 10 cm and perpendicular height 3 cm. Find its area.
15 cm²
Area = ½ × base × height = ½ × 10 × 3 = 15 cm².
7. A triangle has base 8 cm and perpendicular height 13 cm. Find its area.
52 cm²
Area = ½ × base × height = ½ × 8 × 13 = 52 cm².
8. A triangle has base 16 cm and perpendicular height 14 cm. Find its area.
112 cm²
Area = ½ × base × height = ½ × 16 × 14 = 112 cm².
9. A triangle has base 6 cm and perpendicular height 13 cm. Find its area.
39 cm²
Area = ½ × base × height = ½ × 6 × 13 = 39 cm².
10. 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.
11. A triangle has base 16 cm and perpendicular height 18 cm. Find its area.
144 cm²
Area = ½ × base × height = ½ × 16 × 18 = 144 cm².
12. A triangle has base 16 cm and perpendicular height 13 cm. Find its area.
104 cm²
Area = ½ × base × height = ½ × 16 × 13 = 104 cm².

12 questions · Seed 44 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 10-12

Area of a triangle

Take your time. Show your thinking.

1. A triangle has base 28 cm and perpendicular height 14 cm. Find its area.
28 cm · 14 cm · Area of a triangle
2. A triangle has base 12 cm and perpendicular height 17 cm. Find its area.
12 cm · 17 cm · Area of a triangle
3. A triangle has base 26 cm and perpendicular height 10 cm. Find its area.
26 cm · 10 cm · Area of a triangle
4. A triangle has base 20 cm and perpendicular height 16 cm. Find its area.
20 cm · 16 cm · Area of a triangle
5. A triangle has base 28 cm and perpendicular height 11 cm. Find its area.
28 cm · 11 cm · Area of a triangle
6. A triangle has base 10 cm and perpendicular height 3 cm. Find its area.
10 cm · 3 cm · Area of a triangle
7. A triangle has base 8 cm and perpendicular height 13 cm. Find its area.
8 cm · 13 cm · Area of a triangle
8. A triangle has base 16 cm and perpendicular height 14 cm. Find its area.
16 cm · 14 cm · Area of a triangle
9. A triangle has base 6 cm and perpendicular height 13 cm. Find its area.
6 cm · 13 cm · Area of a triangle
10. A triangle has base 10 cm and perpendicular height 10 cm. Find its area.
10 cm · 10 cm · Area of a triangle
11. A triangle has base 16 cm and perpendicular height 18 cm. Find its area.
16 cm · 18 cm · Area of a triangle
12. A triangle has base 16 cm and perpendicular height 13 cm. Find its area.
16 cm · 13 cm · Area of a triangle

12 questions · Seed 44 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 10-12

Area of a triangle

Answers and reasoning. Review before teaching.

1. A triangle has base 28 cm and perpendicular height 14 cm. Find its area.
196 cm²
Area = ½ × base × height = ½ × 28 × 14 = 196 cm².
2. 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.
3. A triangle has base 26 cm and perpendicular height 10 cm. Find its area.
130 cm²
Area = ½ × base × height = ½ × 26 × 10 = 130 cm².
4. A triangle has base 20 cm and perpendicular height 16 cm. Find its area.
160 cm²
Area = ½ × base × height = ½ × 20 × 16 = 160 cm².
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. A triangle has base 10 cm and perpendicular height 3 cm. Find its area.
15 cm²
Area = ½ × base × height = ½ × 10 × 3 = 15 cm².
7. A triangle has base 8 cm and perpendicular height 13 cm. Find its area.
52 cm²
Area = ½ × base × height = ½ × 8 × 13 = 52 cm².
8. A triangle has base 16 cm and perpendicular height 14 cm. Find its area.
112 cm²
Area = ½ × base × height = ½ × 16 × 14 = 112 cm².
9. A triangle has base 6 cm and perpendicular height 13 cm. Find its area.
39 cm²
Area = ½ × base × height = ½ × 6 × 13 = 39 cm².
10. 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.
11. A triangle has base 16 cm and perpendicular height 18 cm. Find its area.
144 cm²
Area = ½ × base × height = ½ × 16 × 18 = 144 cm².
12. A triangle has base 16 cm and perpendicular height 13 cm. Find its area.
104 cm²
Area = ½ × base × height = ½ × 16 × 13 = 104 cm².

12 questions · Seed 44 · Age guidance, not curriculum certification