KLMN is a rectangle which has a breadth of 8 cm. It is divided into 4 triangles. Triangle P is
111 of the area of the rectangle and
13 the area of Triangle R. Triangle Q has an area of 13.5 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
P |
Q |
R |
Rectangle |
1 |
|
|
11 |
1 |
|
3 |
|
1 u |
1.5 u |
3 u |
11 u |
(a)
Area of Triangle Q
= Half of Rectangle KLMN - Triangle R - Triangle P
= (11 u ÷ 2) - 1 u - 3 u
= 1.5 u
1.5 u = 13.5
1 u = 13.5 ÷ 1.5 = 9
Area of the rectangle
= 11 u
= 11 x 9
= 99 cm
2 (b)
Length of the rectangle
= 99 ÷ 8
= 12.375 cm
Perimeter of the rectangle
= 12.375 x 2 + 8 x 2
= 40.75 cm
Answer(s): (a) 99 cm
2; (b) 40.75 cm