The perimeter of a regular pentagon is 41.5 cm. write and solve an equation to determine the length of each side of the pentagon?

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Can you me find the missing length. i attached an image.

Find the area of the triangle formed by the origin and the points of intersection of parabolas y=−3x^2+20 and y=x^2−16.