Find the center and radius of the circle whose equation is x 2 + y 2 - 6x - 2y + 4 = 0 (3,1), r = /6
(-3,-1), r = /6
(3,1) r = 6
(9,1), r = 36

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?