Read the proof.

given: aeec; bddc

prove: △aec ~ △bdc

statement reason
1. aeec; bddc 1. given
2. ∠aec is a rt. ∠; ∠bdc is a rt. ∠ 2. definition of perpendicular
3. ∠aec ≅ ∠bdc 3. all right angles are congruent
4. ? 4. reflexive property
5. △aec ~ △bdc 5. aa similarity theorem
what is the missing statement in step 4?

∠ace ≅ ∠ace
∠eab ≅ ∠dbc
∠eac ≅ ∠eac
∠cbd ≅ ∠dbc

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below:

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?

Measure a and b and find their sum. how are the angles related?