Two rectangles J and K, not drawn to scale, overlap at L. L is the shaded area which is
12 of Rectangle J and
16 of Rectangle K. If the length of Rectangle J is 10 cm and its breadth is 4 cm, what is the area of the unshaded part of rectangles J and K?
| |
J |
K |
Difference |
| Total areas |
2 u |
6 u |
4 u |
| Shaded part |
- 1 u |
- 1 u |
|
| Unshaded parts |
1 u |
5 u |
4 u |
The overlapping shaded part of rectangles J and K is the same.
Area of Rectangle J
= 10 x 4
= 40 cm
2 Area of Rectangle J = 2 u
Area of Rectangle K = 6 u
2 u = 40
1 u = 40 ÷ 2 = 20
Area of unshaded parts of rectangles J and K
= 1 u + 5 u
= 6 u
= 6 x 20
= 120 cm
2 Answer(s): 120 cm
2 
