Two rectangles J and K, not drawn to scale, overlap at L. L is the shaded area which is
15 of Rectangle J and
17 of Rectangle K. If the length of Rectangle J is 15 cm and its breadth is 6 cm, what is the area of the unshaded part of rectangles J and K?
| |
J |
K |
Difference |
| Total areas |
5 u |
7 u |
2 u |
| Shaded part |
- 1 u |
- 1 u |
|
| Unshaded parts |
4 u |
6 u |
2 u |
The overlapping shaded part of rectangles J and K is the same.
Area of Rectangle J
= 15 x 6
= 90 cm
2 Area of Rectangle J = 5 u
Area of Rectangle K = 7 u
5 u = 90
1 u = 90 ÷ 5 = 18
Area of unshaded parts of rectangles J and K
= 4 u + 6 u
= 10 u
= 10 x 18
= 180 cm
2 Answer(s): 180 cm
2 
