STUV is a rectangle which has a breadth of 5 cm. It is divided into 4 triangles. Triangle W is
111 of the area of the rectangle and
13 the area of Triangle Y. Triangle X has an area of 13.5 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
W |
X |
Y |
Rectangle |
1 |
|
|
11 |
1 |
|
3 |
|
1 u |
1.5 u |
3 u |
11 u |
(a)
Area of Triangle X
= Half of Rectangle STUV - Triangle Y - Triangle W
= (11 u ÷ 2) - 1 u - 3 u
= 1.5 u
1.5 u = 13.5
1 u = 13.5 ÷ 1.5 = 9
Area of the rectangle
= 11 u
= 11 x 9
= 99 cm
2 (b)
Length of the rectangle
= 99 ÷ 5
= 19.8 cm
Perimeter of the rectangle
= 19.8 x 2 + 5 x 2
= 49.6 cm
Answer(s): (a) 99 cm
2; (b) 49.6 cm