Short answer: B
Remark
A 45 degree angle means that the height is the same length as part of the base. But which part?
Givens
b1 = 9 feet
b2 = 23 feet
and the 45 degree angle on the right.
Determine the height.
The part of the base that is associated with the 45 degree angle is found by subtracting b1 from b2
b2 - b1 = 23 - 9 = 14
So 14 is also the height
Find the Area
A = 1/2 (b1 + b2)*h
b1 = 9
b2 = 23
h = 14
Area = 1/2(9 + 23) * 14
Area = 1/2 (32) * 14
Area = 16 * 14
Area = 224 <<<< answer