☰ Contents · Geometry

Angle sum and exterior angle of a triangle

Lessons 37–38 · 2 lessons · Geometry Grade 7, corrected and expanded 3rd edition. Yangiyo‘l Poligraf Servis, Tashkent, 2017 (approved by the Ministry of Public Education)
Answers are for parents and teachers.
1
In △ABC, ∠A = 49°, ∠C = 83°. Find ∠B (degrees).
2
Angles in ratio 2 : 5 : 8. Find the largest (degrees).
3
A base angle of an isosceles triangle is 65°. Find the apex angle (degrees).
4
An exterior angle is 118° and the two non-adjacent interior angles are equal. Find each (degrees).
5
Write the main idea of the proof of the angle sum theorem.