Simplify the expression 3 x + 6x + 2x

HELP PLZ

How many sides does a regular polygon have if each exterior angle measures 72a.3b.4c.5d.6

What is the difference between the predicted value and the actual value

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?