FGHJ is a rectangle which has a breadth of 7 cm. It is divided into 4 triangles. Triangle K is
114 of the area of the rectangle and
14 the area of Triangle M. Triangle L has an area of 18 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
K |
L |
M |
Rectangle |
1 |
|
|
14 |
1 |
|
4 |
|
1 u |
2 u |
4 u |
14 u |
(a)
Area of Triangle L
= Half of Rectangle FGHJ - Triangle M - Triangle K
= (14 u ÷ 2) - 1 u - 4 u
= 2 u
2 u = 18
1 u = 18 ÷ 2 = 9
Area of the rectangle
= 14 u
= 14 x 9
= 126 cm
2 (b)
Length of the rectangle
= 126 ÷ 7
= 18 cm
Perimeter of the rectangle
= 18 x 2 + 7 x 2
= 50 cm
Answer(s): (a) 126 cm
2; (b) 50 cm