In the figure, not drawn to scale, 40% of the triangle BED is shaded. The ratio of the shaded part of the circle to the unshaded part of the circle is 2 : 9. What percentage of the rectangle ABDC is unshaded?
Shaded
Circle |
Unshaded
Circle |
Shaded
Triangle |
Total
Triangle |
| 2x1 |
9x1 |
2x1 |
5x1 |
| 2 u |
9 u |
2 u |
5 u |
40% =
40100 =
25 The shaded part of the figure is the repeated identity. Make the shaded part of the figure the same. LCM of 2 and 2 is 2.
Total area of the rectangle
= 2 x Total triangle
= 2 x 5 u
= 10 u
Unshaded areas
= 10 u - 2 u
= 8 u
Percentage of Rectangle ABDC that is unshaded
=
Unshaded areasArea of Rectangle ABDC x 100%
=
810 x 100%
= 80%
Answer(s): 80%
