Just tell me how to set up the equation.

ABD = 149

Step-by-step explanation:

The exterior angle of a triangle is the sum of the opposite interior angles

50x -1 = 22x+83

Subtract 22x from each side

50x-22x-1 = 22x-22x+83

28x -1 = 83

Add 1 to each side

28x-1+1 = 83+1

28x =84

Divide by 28

28x/28x = 84/28

x = 3

Now we want to find ABD

ABD = 50x-1

         =50(3)-1

         150-1

           149

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc