9514 1404 393
Answer:
 8) 42 in²
 9) 33 cm²
 10) 112 yd²
Explanation:
8) The area is given by the formula ...
 A = 1/2(b1 +b2)h
 A = (1/2)(9 in +5 in)(6 in) = 42 in²
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9) The area is half the product of the lengths of the diagonals.*
 A = 1/2(d1)(d2)
 A = 1/2(6 cm)(11 cm) = 33 cm²
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10) As in the previous problem, ...
 A = 1/2(14 yd)(16 yd) = 112 yd²
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* This formula works for any quadrilateral with perpendicular diagonals.