HJKL is a rectangle which has a breadth of 12 cm. It is divided into 4 triangles. Triangle M is
114 of the area of the rectangle and
14 the area of Triangle P. Triangle N has an area of 48 cm
2.
- Find the area of the rectangle.
- Find the perimeter of the rectangle.
M |
N |
P |
Rectangle |
1 |
|
|
14 |
1 |
|
4 |
|
1 u |
2 u |
4 u |
14 u |
(a)
Area of Triangle N
= Half of Rectangle HJKL - Triangle P - Triangle M
= (14 u ÷ 2) - 1 u - 4 u
= 2 u
2 u = 48
1 u = 48 ÷ 2 = 24
Area of the rectangle
= 14 u
= 14 x 24
= 336 cm
2 (b)
Length of the rectangle
= 336 ÷ 12
= 28 cm
Perimeter of the rectangle
= 28 x 2 + 12 x 2
= 80 cm
Answer(s): (a) 336 cm
2; (b) 80 cm