
2. 
The perpendicular bisectors of _{}ABC meet at point G. If _{} = 16, _{} = 5, and _{} = 3, find _{}.




5. 
The governor wants to build a new library for three cities X, Y, and Z. If the distance between each two cities is 20 kilometers, and the location of the new library will be in equidistance to all three cities, what is the distance between the new library and city X? 

6. 
You want to prove that the perpendicular bisector of the base of an isosceles triangle is also the angle bisector of the vertex. Which postulate can NOT be used in your proof? 
