A52 A Demonstration of 
GE::GE:ME, or ME, GE, NG, FE 
54 are four continual. proportionals. Which 
as the 54th Proposition. ‘ 
Its converse is here also proved. And 
likewise the following, viz. FE being di- 
vided by the 60th Proposition, so that 
GE : EH:: EH: FE, if EL be. taken 
= AE = GE, a circle drawn through the 
points A, H, L will cut FE produced in K 
so that EK, GE, HE, FE, are four con- 
tinual proportionals. 
Prop. LX. If an isoseeles triangle be inscribed in a semi- 
circle and one of the equal sides produced, and if from any 
point Ein a diametera perpendicular thereto be drawn to 
cut the side, the circle, and the side produced in the points 
G, H and F respectively ; then I say that EG, EHand EF 
are continual proportionals. 
