The figure is made up of two squares and a triangle. The ratio of the area of Triangle M to that of Square P is 7 : 1. The ratio of the shaded area to that of the unshaded area is 1 : 3. If the difference between areas of Triangle M and Square N is 391 cm
2, what is the area of Square P?
Area of Triangle M |
Area of Square P |
Shaded area |
Unshaded area |
Total area |
7x4 |
1x4 |
|
|
7x4 |
|
|
1x7 |
3x7 |
4x7 |
28 u |
4 u |
7 u |
21 u |
28 u |
Area of Triangle M = Total area of the figure
Total area is the unchanged total. Make the total area the same.
LCM of 7 and 4 = 28
Area of Square N
= 7 u + 4 u
= 11 u
Difference between the areas of Triangle M and Square N
= 28 u - 11 u
= 17 u
17 u = 391
1 u = 391 ÷ 17 = 23
Area of Square P
= 4 u
= 4 x 23
= 92 cm
2 Answer(s): 92 cm
2