Question

The isosceles trapezoid is part of an isosceles triangle with 38 vertex angle. what is the measure of an acute best angle of the trapezoid? what is the measure of an obtuse base angle of the trapezoid?

Answer 1

The base angle of any isosceles triangle is the complement of half the vertex angle. In this case, that is
.. 90° -(38°/2) = 71°

The obtuse base angle of the isosceles trapezoid is the supplement of this,
.. 180° -71° = 109°.