In the figure, not drawn to scale, 40% of the triangle CFE is shaded. The ratio of the shaded part of the circle to the unshaded part of the circle is 3 : 5. What percentage of the rectangle BCED is unshaded?
Shaded Circle |
Unshaded Circle |
Shaded Triangle |
Total Triangle |
3x2 |
5x2 |
2x3 |
5x3 |
6 u |
10 u |
6 u |
15 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 3 is 6.
Total area of the rectangle
= 2 x Total triangle
= 2 x 15 u
= 30 u
Unshaded areas
= 30 u - 6 u
= 24 u
Percentage of Rectangle BCED that is unshaded
=
Unshaded areasArea of Rectangle BCED x 100%
=
2430 x 100%
= 80%
Answer(s): 80%