Answer:
D) 78 units²
Explanation:
The left, bottom, and right vertex coordinates are ...
(1, 8), (4, 5), and (17, 18)
Then the length of the downward-sloping bottom edge is ...
d = √((4-1)² +(5-8)²) = √18 = 3√2
and the length of the upward-sloping bottom edge is ...
d = √((17-4)² +(18-5)²) = 13√2
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The area is the product of these edge lengths:
Area = (3√2)(13√2) = 39·2 = 78 . . . . units²
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The distance between points (x1, y1) and (x2, y2) is given by the distance formula ...
d = √((x2-x1)² +(y2-y1)²)