Page:First six books of the elements of Euclid 1847 Byrne.djvu/82

N a right angled triangle the ſquare on the hypotenuſe is equal to the ſum of the ſquares of the ſides, ( and ).

On , and deſcribe ſquares, (pr. 46.)

Draw $\parallel$ (pr. 31)

alſo draw and .

$=$ ,

To each add $\therefore$ $=$ ,

$=$ and $=$ ;

$\therefore$ $=$

Again, becauſe $\parallel$