Sarah's heart beats 2,760 times during 20 minutes of rowing. While resting, Sarah records
her heart beating 11 times in 10 seconds.
What is the difference between Sarah's heart
rate when she is rowing versus resting?

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.