F a parallelogram and a triangle are upon the ſame baſe and between the ſame parallels and , the parallelogram is double the triangle.
Draw the diagonal;
Then = {\displaystyle =} (pr. 37.)[1]
= {\displaystyle =} twice (pr. 34.)
∴ {\displaystyle \therefore } = {\displaystyle =} twice .[2]
Q.E.D.
F a parallelogram 
and a triangle 
are upon the ſame baſe
and between the ſame parallels 
and , the parallelogram is double the triangle.
