The sum of the three angles of an isosceles trapezoid is 250 °. find the smaller of the corners of the trapezoid.

Since a trapezoid is a convex quadrilateral, the sum of its interior angles is 360.

Then one of the corners of the trapezoid is: 360 – 250 = 110.

This is the obtuse angle of the trapezoid. Let the angle ABC = 110.

In a trapezoid, the sum of the angles at its lateral side is 180, the angle BAD + ABC = 180, then the angle BAD = 180 – ABC = 180 – 110 = 70.

By condition, the trapezoid ABCD is isosceles, then the angle ADC = BAD = 70, the angle BCD = ABC = 110.

Answer: The smaller angle of the trapezoid is 70.