Find the constant of proportionality (r) in the equation y=rx

What situation is an example of an observational study

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.

Which spreadsheet would be used to compute the first nine terms of the geometric sequence a^n=32•(1/2)n-1