Hi there!
In order to solve, we need to use the formula for the area of a circle, and the angle given to find the area of the sector. Then, subtract the area of the triangle to find the area of the segment. We would use the equation : A = x/360 (pi * r^2) - 1/2(b * h). We need to plug in 90 for the angle measurement, 8 for the radius, and 8 for both the base and height.
WORK:
A = 90/360 (pi * 64) - 1/2(64)
A = 1/4(64pi) - 32
A = 16pi - 32 = ~ 18.3ft^2
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!