I need help with the EC question

Complete the steps, which describe how to find the area of the shaded portion of the circle. find the area of the sector by multiplying the area of the circle by the ratio of the to 360. subtract the area of the triangle from the area of the sector.

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

(60 points) explain this in detail