KLMN is a rectangle which has a breadth of 7 cm. It is divided into 4 triangles. Triangle P is
113 of the area of the rectangle and
14 the area of Triangle R. Triangle Q has an area of 21 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
P |
Q |
R |
Rectangle |
1 |
|
|
13 |
1 |
|
4 |
|
1 u |
1.5 u |
4 u |
13 u |
(a)
Area of Triangle Q
= Half of Rectangle KLMN - Triangle R - Triangle P
= (13 u ÷ 2) - 1 u - 4 u
= 1.5 u
1.5 u = 21
1 u = 21 ÷ 1.5 = 14
Area of the rectangle
= 13 u
= 13 x 14
= 182 cm
2 (b)
Length of the rectangle
= 182 ÷ 7
= 26 cm
Perimeter of the rectangle
= 26 x 2 + 7 x 2
= 66 cm
Answer(s): (a) 182 cm
2; (b) 66 cm