EFGH is a rectangle which has a breadth of 10 cm. It is divided into 4 triangles. Triangle J is
114 of the area of the rectangle and
14 the area of Triangle L. Triangle K has an area of 38 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
J |
K |
L |
Rectangle |
1 |
|
|
14 |
1 |
|
4 |
|
1 u |
2 u |
4 u |
14 u |
(a)
Area of Triangle K
= Half of Rectangle EFGH - Triangle L - Triangle J
= (14 u ÷ 2) - 1 u - 4 u
= 2 u
2 u = 38
1 u = 38 ÷ 2 = 19
Area of the rectangle
= 14 u
= 14 x 19
= 266 cm
2 (b)
Length of the rectangle
= 266 ÷ 10
= 26.6 cm
Perimeter of the rectangle
= 26.6 x 2 + 10 x 2
= 73.2 cm
Answer(s): (a) 266 cm
2; (b) 73.2 cm