The figure, not drawn to scale, shows a rectangle, CDEF, which is divided in 4 parts, G, H, J, and K. The ratio of the area of K to the area of J is 1 : 4. The ratio of the area of J to the area of H is 5 : 6. If the area of G is 189 cm
2, what is the area of the rectangle CDEF?
K |
J |
H |
G |
1x5 |
4x5 |
|
|
|
5x4 |
6x4 |
|
5 u |
20 u |
24 u |
9 u |
Area J is the repeated identity.
LCM of 4 and 5 = 20
Half of the area of the rectangle
= Area K + Area H
= 5 u + 24 u
= 29 u
Area of G
= Half of the area of the rectangle - Area J
= 29 u - 20 u
= 9 u
9 u = 189
1 u = 189 ÷ 9 = 21
Area of the rectangle
= 29 u x 2
= 58 u
= 58 x 21
= 1218 cm
2 Answer(s): 1218 cm
2