composite figures..

Geometry Level 2

The red, blue and green regions are all semi-circles and the yellow region is a right triangle. Given that the area of the red region is $\dfrac{2025 \pi}{8}$ , green region is $\dfrac{729 \pi}{8}$ and blue region is $162 \pi$ . Find the perimeter of the yellow region (triangle).

The answer is 108.

1 solution

Marta Reece
Mar 18, 2018

Radii are $\sqrt{2\cdot\frac{2025}8}=\frac{45}2, \sqrt{2\cdot\frac{729}8}=\frac{27}2,$ and $\sqrt{2\cdot162}=18$ .

The sides are double that, $45, 27, 36$ and the perimeter is their sum $45+27+36=\boxed{108}$ .

composite figures..

The answer is 108.

1 solution

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