How many square feet of grass are there on the trapezoidal field with a height of 75 ft and bases of 125ft and 81 ft

Answer 1

75 (125 + 81) / 2
In other words use the average height
to show why draw verticals at the two ends of the short top
you cut off identical triangles at the ends
put those triangles together now and look at the area added to the interior rectangle by them,

Answer 2

area of trap = (1/2)(sum of bases)(height between the bases)
= (1/2)(125+81)(75)
= ..... ft^2