Triangle A is rotated 90-degrees clockwise about the origin. Which triangle is the image of this rotation? * B
C
D
none of these

The answer is B

Step-by-step explanation:

The equation for a 90 degree clockwise rotation is (x,y) -> (y,-x)

so (-2, 2) -> (2,2). You can also look up "rotation calculator", it really helped me get through this unit haha

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4

i would say true? if the unit was informational and it "refreshed your understanding", then true.