Books  Books 31  32 of 32 on The area of a trapezoid is equal to onehalf the sum of the parallel sides multiplied.... 
The area of a trapezoid is equal to onehalf the sum of the parallel sides multiplied by the altitude. Sheet Metal Drafting, Prepared in the Extension Division of the University ...  Page 23 by Ellsworth M. Longfield  1921  236 pages Full view 
