Question

**Please help**
WRITE THE GIVEN AND PROVE
2)The bisector of the vertex angle of an Isosceles triangle is perpendicular to the base.

3) The median of the base of an isosceles triangle divides the triangle into 2 cong. triangles.

Answer 1

2)
2 triangles are congruent easily and 2x + 2d = 180 then x+d + 90
thus y= 90degree
3) 2 sides + 1 angle between