This is an isosceles triangle. The two angles opposite the two equal sides are equal. With this knowledge, we now know that the angles are 61, 61, x.
We also know that the sum of all the angles of a triangle is equal to 180 degrees.
61 + 61 + x = 180.
Combine like terms.
122 + x = 180
Subtract 122 from both sides.
x = 58 degrees
