Area, volume and surface area

The area of a triangle

Name: ______________________________Date: ______________Score: ______ / 20

1.
A triangle has a base of 4 cm and a perpendicular height of 17 cm. What is its area?
cm²
2.
Which height do you use in the area formula for a triangle?
1. Athe perpendicular height
2. Bthe longest side
3. Cthe sloping side
3.
A compound shape is made of a 7 cm by 5 cm rectangle and a triangle of base 3 cm and height 2 cm. What is the total area?
cm²
4.
Two identical triangles, each with base 12 cm and height 6 cm, are put together to make a rectangle. What is the area of the rectangle?
cm²
5.
Match each triangle to its area.
Write the letter of the matching item in each box:
?base 2 cm, height 8 cm
?base 4 cm, height 8 cm
?base 6 cm, height 8 cm
A8 cm²
B16 cm²
C24 cm²
6.
A triangle has an area of 84 cm² and a base of 14 cm. What is its perpendicular height?
cm
7.
A compound shape is made of a 6 cm by 4 cm rectangle and a triangle of base 10 cm and height 7 cm. What is the total area?
cm²
8.
Two identical triangles, each with base 11 cm and height 10 cm, are put together to make a rectangle. What is the area of the rectangle?
cm²
9.
A triangle has an area of 78 cm² and a base of 13 cm. What is its perpendicular height?
cm
10.
A compound shape is made of a 3 cm by 4 cm rectangle and a triangle of base 9 cm and height 6 cm. What is the total area?
cm²
11.
Two identical triangles, each with base 9 cm and height 8 cm, are put together to make a rectangle. What is the area of the rectangle?
cm²
12.
What is the area of the RECTANGLE that surrounds a triangle with base 8 cm and height 4 cm?
cm²
13.
A triangle has a base of 10 cm and a height of 7 cm. What is its area in square millimetres?
mm²
14.
A compound shape is made of a 9 cm by 2 cm rectangle and a triangle of base 4 cm and height 4 cm. What is the total area?
cm²
15.
A triangle has base 2 cm and height 12 cm. What is its area?
1. A24 cm²
2. B12 cm²
3. C14 cm²
16.
A triangle has a base of 6 cm and a perpendicular height of 4 cm. What is its area?
cm²
17.
What is the area of the RECTANGLE that surrounds a triangle with base 12 cm and height 8 cm?
cm²
18.
A triangle has base 6 cm and height 5 cm. What is its area?
1. A30 cm²
2. B11 cm²
3. C15 cm²
19.
A triangle has a base of 16 cm and a height of 3 cm. What is its area in square millimetres?
mm²
20.
What is the area of the RECTANGLE that surrounds a triangle with base 6 cm and height 7 cm?
cm²

Answer key

Area, volume and surface area — The area of a triangle

1.34 cm²
2.A. the perpendicular height
3.38 cm²
4.72 cm²
5.base 2 cm, height 8 cm → 8 cm²; base 4 cm, height 8 cm → 16 cm²; base 6 cm, height 8 cm → 24 cm²
6.12 cm
7.59 cm²
8.110 cm²
9.12 cm
10.39 cm²
11.72 cm²
12.32 cm²
13.3500 mm²
14.26 cm²
15.B. 12 cm²
16.12 cm²
17.96 cm²
18.C. 15 cm²
19.2400 mm²
20.42 cm²