Math 9 Area of Triangles and Trapezoids Worksheet 4-2

Journeys Page 199

Name ______

1.  Find the area.

2.  Sketch the triangle. Then find the area.

a) base 7.2 m, height 3.0 m b) base 9.5 cm, height 21 mm

c) base 86 cm, height 1.2 m d) base 2x, height x + 2

3.  One litre of paint covers 11 m2 of a surface.

a)  Find the area of the Marine World sign.

b)  Find the number of litres of paint needed to paint the back of the sign.

4.  Sketch the trapezoid. Then find the area.

a) a = 7.8 cm, b = 9.1 cm, h = 5.2 cm b) a = 2.1 m, b = 3.0 m, h = 82 cm

c) a = x, b = x + 4, h = 8 m d) a = x, b = 5 cm, h = 2x

5.  The transom of a row boat has the shape of a trapezoid. The distance across the top is 1.0 m, the distance across the bottom is 0.70 m, and the height is 0.50 m. Find the area of the transom.

6.  Find the area.

7.  Find the measure of the height.

a)  of a trapezoid with area 144 cm2 and parallel sides 10.0 cm and 14.0 cm.

b)  of a triangle with area x2 + 3x and a base x.

8.  a) How much grass seed is needed to cover the lawn area? 1.5 kg of grass seed covers 10.0 m2.

b) One bag of fertilizer covers 300 m2. How many bags of fertilizer are needed?

9.  A section of a city street, 225 m long and 22 m wide, is to be resurfaced and curbs put in. Curbing costs $3.04/m and paving $14.27/m2. Find the total cost of the work.

10.  Find the height of the rectangle.

a)  with area 24 cm2 and base 3.2 cm

b)  with area x2 – x – 12 and base x – 4.