The value of the base BC is 44
It is important to note that the non-parallel sides and the base angles of an isosceles trapezoid are congruent.
Then, from the information given, we have;
This is expressed as;
EF = Base BC + Base AD/2
Substitute the values into the equation
18.5x + 8 = 22x + 17x + 12/2
cross multiply
2(18. 5x + 8) = 22x + 17x + 12
expand the bracket
37x + 16 = 39x + 12
collect like terms
37x - 39x = 12 - 16
subtract like terms
-2x = -4
x = 2
But BC = 22x = 22(2 ) = 44
Thus, the value of the base BC is 44
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