8-solve problem

1) consider = {X,,{a},{a, b}, {a, c, d}, {a, b, e}, {a, b,c, d}} on
X = {a, b,c, d,e) Find A' ,Ā, A°, A^b, A^ext, N(c) of the subset A = {c, d, e}

2) For a subset A of a space X, show that (A°, A^b, A^ext} Form a partition of X

What aspects of lines have to be diffrent

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?

How can you tell when x and y are not directly proportional?