What is the length of the missing base of the trapezoid?

3 in
8 in

area= 21 in2

Lines p and q intersect. find the value of b. show your work. cite any theorems you use.

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.