A scatter plot has a negative, linear correlation. which statement is true about the relationship between the x-and y-values

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)