Answer: 102
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We'll use the formula
A = h*(b1+b2)/2
where
A = area of trapezoid
h = height
b1 & b2 are the parallel bases
In this case,
b1 = 6+7 = 13
b2 = 21
h = 6
Making the area to be
A = h*(b1+b2)/2
A = 6*(13+21)/2
A = 6*(34)/2
A = 204/2
A = 102
Side Note: We don't use the slanted side of 10 cm at all