Question

in a isosceles triangle the vertex angle is twice the each base angle find the vertex angle

Answer 1

as we know in isosceles triangle both base angles are equal
Let the base angle be x
Then vertical angle = 2x
ATQ
x+x+2x=180
4x=180
x=180/4
45
So verticle angle =2*45=90

Answer 2

In an isosceles triangle base angles are equal.
Now let each base angle = x
Vertex angle=2x
=> x+x+2x=180 ( Sum of interior angles of triangle)
=> 4x=180
=> x=180/4= 45
.: Vertex angle is 2x= 2*45= 90 degrees. (Ans.)