A circle has a radius of 14 cm. Another circle has a radius of 7 cm. The centre of the second circle lies on the circumference of the first. Find The common area for both circles.
My elaborate solution wasn't posted (I think because I didn't close the preview???)
Anyway, I also got the answer 68.75 by dividing the area in two parts and adding them.
It was 14² * (2 arcsin(0.25) - 7 * √15/64) + 7² * (π/2 - arcsin(0.25) - √15/16)