Question

Set up an equation in the following case:
In an isosceles triangle, the vertex angle is twice either base angle. (Let the base angle be $b$ in degrees. Remember that the sum of angles of a triangle is ${180}^{\circ }$. )

Answer 1

In isosceles triangle two angles are equal while third is different
Let the base angle of the isosceles triangle be $b$,
so vertex angle $=2b$. [ as given]
We know that the sum of all three angles in a triangle is equal to ${180}^{\circ }$
So equation will be $2b+b+b={180}^{\circ }$
$\therefore 4b={180}^{\circ }$ is the required equation.