X+ x + 2 + x + 4 = 81 ( the answer is not 25 , 65, or ! )

X + X + 2 + X + 4 = 81

First, combine numbers and Xs.

answer: we will use similar property.

explanation:

since, if two figure are similar then the ratios of their corresponding sides are equal.

in the given figure , in pentagon abcde, vertices a,b,c,d and e are given so the sides are obtained with the of distance formula which is unit

so, with of this formula , ab=   2√2,bc=4, cd= √10, de=√10 and ea=2√2

similarly, fg=√2, gh=2, hi=1.58114,ij= 1.58114 and jf=√2

since, here,

thus, these two shapes are similar.