Coordinates are: H ( 0, 0 ) and G ( 2 a, 0 ). Coordinates of the midpoint are: x = ( x 1 + x 2 ) / 2 y = ( y 1 + y 2 ) / 2 The midpoint of HG: x = ( 0 + 2 a ) / 2 = 2 a / 2 = a y = ( 0 + 0 ) / 2 = 0 / 2 = 0 Answer: D ) ( a, 0 )
(Excel works great with this and will solve it for you, use the PMT function and insert the numbers provided. It will show a (-) but that is because a positive PV is placed.)