Find the measures of the angles of an isosceles obtuse triangle with one angle measuring 20.

Answer 1

An obtuse triangle is one that has one angle greater than 90°. If that's the case, then, since the total of all 3 angles is 180°, then the other angles must be smaller than 90°. Since it's an isosceles triangle, then the two base angles must be the ones that are 20°. So 180° - 20° - 20° = 140° making the measures of the angles 140°, 20°, and 20°.