EFGH is a rectangle which has a breadth of 7 m. It is divided into 4 triangles. Triangle J is
111 of the area of the rectangle and
13 the area of Triangle L. Triangle K has an area of 21 m
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
J |
K |
L |
Rectangle |
1 |
|
|
11 |
1 |
|
3 |
|
1 u |
1.5 u |
3 u |
11 u |
(a)
Area of Triangle K
= Half of Rectangle EFGH - Triangle L - Triangle J
= (11 u ÷ 2) - 1 u - 3 u
= 1.5 u
1.5 u = 21
1 u = 21 ÷ 1.5 = 14
Area of the rectangle
= 11 u
= 11 x 14
= 154 m
2 (b)
Length of the rectangle
= 154 ÷ 7
= 22 m
Perimeter of the rectangle
= 22 x 2 + 7 x 2
= 58 m
Answer(s): (a) 154 m
2; (b) 58 m