The structure shown below will be built for a carnival. the exterior surfaces are gonna be painted. what is the total area of the exterior surfaces that needs to be painted

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

the answer is 18 units because there are 18 small cubes inside the rectangle

hope this and p.s i am also in k12

step-by-step explanation: