CDEF is a rectangle which has a breadth of 10 m. It is divided into 4 triangles. Triangle G is
114 of the area of the rectangle and
14 the area of Triangle J. Triangle H has an area of 36 m
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
G |
H |
J |
Rectangle |
1 |
|
|
14 |
1 |
|
4 |
|
1 u |
2 u |
4 u |
14 u |
(a)
Area of Triangle H
= Half of Rectangle CDEF - Triangle J - Triangle G
= (14 u ÷ 2) - 1 u - 4 u
= 2 u
2 u = 36
1 u = 36 ÷ 2 = 18
Area of the rectangle
= 14 u
= 14 x 18
= 252 m
2 (b)
Length of the rectangle
= 252 ÷ 10
= 25.2 m
Perimeter of the rectangle
= 25.2 x 2 + 10 x 2
= 70.4 m
Answer(s): (a) 252 m
2; (b) 70.4 m