TUVW is a rectangle which has a breadth of 12 cm. It is divided into 4 triangles. Triangle X is
112 of the area of the rectangle and
13 the area of Triangle Z. Triangle Y has an area of 40 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
X |
Y |
Z |
Rectangle |
1 |
|
|
12 |
1 |
|
3 |
|
1 u |
2 u |
3 u |
12 u |
(a)
Area of Triangle Y
= Half of Rectangle TUVW - Triangle Z - Triangle X
= (12 u ÷ 2) - 1 u - 3 u
= 2 u
2 u = 40
1 u = 40 ÷ 2 = 20
Area of the rectangle
= 12 u
= 12 x 20
= 240 cm
2 (b)
Length of the rectangle
= 240 ÷ 12
= 20 cm
Perimeter of the rectangle
= 20 x 2 + 12 x 2
= 64 cm
Answer(s): (a) 240 cm
2; (b) 64 cm