Help pls, giving brainlist to anyone who answers. The choices are 18
54
72
150
show work pla

54 feet

Step-by-step explanation:

We want to set up a ratio of height to shadow length.

3/5=x/90

We notice that 90 is 18 times 5

We can multiply 3/5 by 18/18 to set the denominators equal

3(18)/5(18)=x/90

54/90=x/90

54=x

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

step-by-step explanation: 2