The sum of the two angles of an isosceles trapezoid is 178 degrees. Find the larger angle of the trapezoid.

1. A, B, C, D – the tops of the trapezoid. ∠А + ∠Д = 178 °.

2. In an isosceles trapezoid, the angles at its base are equal. ∠А = ∠Д = 178 °: 2 = 89 °.

3. According to one of the properties of an isosceles trapezoid, the total value of the angles opposite each other is 180 °. Using it, we calculate the degree measure ∠С:

∠С = 180 ° – ∠А = 180 ° – 89 ° = 91 °.

4. ∠В is also 91 °, since it is also at the base of ВС.

Answer: large trapezoid angles ∠В = ∠С = 91 °.