In an isosceles triangle, the base angle is 30 degrees. What is the apex angle?

In an isosceles triangle, the angle at the base is equal to each other and the sides are also equal. Then the angles at the base in this triangle are 30 degrees and they are equal. We know that the sum of the degree measures of the angles of any triangle is 180 degrees. Then the third angle at the apex in the triangle is: 180 – (30 + 30) = 180 – 60 = 120 degrees.
Answer: 120 degrees.



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