Answer: 17.5 square yards
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Work Shown:
base = 5 yards
height = 7 yards
The base and height are always perpendicular to one another
area of triangle = 0.5*(base)*(height)
area of triangle = 0.5*(5)*(7)
area of triangle = 17.5 square yards
The other values aren't used. They're likely thrown in as a distraction.