BCDE is a rectangle which has a breadth of 11 m. It is divided into 4 triangles. Triangle F is
111 of the area of the rectangle and
13 the area of Triangle H. Triangle G has an area of 42 m
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
F |
G |
H |
Rectangle |
1 |
|
|
11 |
1 |
|
3 |
|
1 u |
1.5 u |
3 u |
11 u |
(a)
Area of Triangle G
= Half of Rectangle BCDE - Triangle H - Triangle F
= (11 u ÷ 2) - 1 u - 3 u
= 1.5 u
1.5 u = 42
1 u = 42 ÷ 1.5 = 28
Area of the rectangle
= 11 u
= 11 x 28
= 308 m
2 (b)
Length of the rectangle
= 308 ÷ 11
= 28 m
Perimeter of the rectangle
= 28 x 2 + 11 x 2
= 78 m
Answer(s): (a) 308 m
2; (b) 78 m