What is 2.5^6 please help

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

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?