The figure, not drawn to scale, shows a rectangle, BCDE, which is divided in 4 parts, F, G, H, and J. The ratio of the area of J to the area of H is 1 : 4. The ratio of the area of H to the area of G is 7 : 8. If the area of F is 132 cm
2, what is the area of the rectangle BCDE?
J |
H |
G |
F |
1x7 |
4x7 |
|
|
|
7x4 |
8x4 |
|
7 u |
28 u |
32 u |
11 u |
Area H is the repeated identity.
LCM of 4 and 7 = 28
Half of the area of the rectangle
= Area J + Area G
= 7 u + 32 u
= 39 u
Area of F
= Half of the area of the rectangle - Area H
= 39 u - 28 u
= 11 u
11 u = 132
1 u = 132 ÷ 11 = 12
Area of the rectangle
= 39 u x 2
= 78 u
= 78 x 12
= 936 cm
2 Answer(s): 936 cm
2