The vertex angle of an isosceles triangle is 20° less than the sum of the base angles. which system of equations can be used to find the measure of the vertex and base angles?

Step-by-step explanation:

By definition, we know that the angles of the base of an isosceles triangle are equal.

"The vertex angle of an isosceles triangles is 20° less than the sum of the base angles" this expression can be expressed like

Where is the vertex angle and represents each base angle.

Also, we use the theorem which states that the sum of all interior angles of a triangle is equal to 180°, that is

Now, to find each angle, we replace the first expression into the second one and solve for

Then, we replace this value in one equation to find the other value

Therefore, the vertex angle is 80°, and each base angle is 20°.

(-1,-0.5)

step-by-step explanation: