Practice with Triangles

1. What are the three ways to classify a triangle by its sides?

2. What are the four ways to classify a triangle by its angles?

3. Can a right triangle be equiangular? Explain.

4. The measures of two angles of a triangle are $42^{\circ}$ and $42^{\circ}$. What type of triangle is it?

5. The measures of two angles of a triangle are $120^{\circ}$ and $12^{\circ}$. What type of triangle is it?

Source: CK-12, https://flexbooks.ck12.org/cbook/ck-12-interactive-geometry-for-ccss/section/1.4/primary/lesson/triangles-geo-ccss/

 This work is licensed under CK-12 Curriculum Materials License.

1. Scalene, isosceles, equilateral

2. Acute, right, obtuse, equiangular

3. No, because equiangular triangles have all angles $60^{\circ}$. A right triangle must have one angle that is $90^{\circ}$.

4. Isosceles and obtuse.

5. Scalene and obtuse.