×
Back to all chapters

# Classification of Triangles

Can a scalene triangle be obtuse? Is an equilateral triangle always acute?

# Triangles - Classification By Angles

If $$\angle A = 45 ^\circ, \angle B = 35 ^\circ$$ and $$\angle C = 100 ^\circ$$ in the above triangle, what type of triangle is $$\triangle ABC?$$

If $$ABCDEFGH$$ is a cube with side length $$5,$$ what is $$\angle DEG ?$$

The length of $$\overline {AB}$$ is the same as that of $$\overline {AC}$$ in the above triangle. If $$\angle B =74^\circ,$$ what is $$\angle C ?$$

Suppose that $$\angle A = 80 ^\circ, \angle B = 55 ^\circ$$ and $$\angle C = 45 ^\circ .$$ If points $$D, E$$ and $$F$$ are the midpoints of $$\overline{BC}, \overline{CA}$$ and $$\overline{AB},$$ respectively, what type of triangle is $$\triangle DEF ?$$

Note: The above diagram is not drawn to scale.

What do we call a triangle which has exactly 2 equal angles?

×