The rectangle is divided into four parts H, J, K and L. The ratio of Part H to Part J is 7 : 3 and the ratio of Part J to Part K is 3 : 1.
- Find the ratio of Part H to Part J to Part K.
- Given that Part L is 27 cm2 , find the area of the rectangle.
(a)
| H |
J |
K |
L |
| 7x1 |
3x1 |
|
|
| |
3x1 |
1x1 |
|
| 7 u |
3 u |
1 u |
27 cm2 |
Part J is the repeated identity.
LCM of 3 and 3 = 3
Part H : Part J : Part K = 7 : 3 : 1
(b)
Part H + Part J = Half of the rectangle
Part K + Part L = Half of the rectangle
Part H + Part J and Part K + Part L are equal.
Part H + Part J = Part K + Part L
7 u + 3 u = 1 u + 27
7 u + 3 u - 1 u = 27
9 u = 27
1 u = 27 ÷ 9 = 3
Area of the rectangle
= 2 x (1 u + 27)
= 2 x (1 x 3 + 27)
= 2 x (3 + 27)
= 2 x 30
= 60 cm
2 Answer(s): (a) 7 : 3 : 1; (b) 60 cm
2 
