Angle-Side Relationships in Triangles

Angle-Side Relationships in Triangles

Read each question carefully and answer to the best of your ability. Show all your work where applicable.

1. In triangle ABC, if angle A = 60°, angle B = 40°, and angle C = 80°, which side is the longest?

2. If two sides of a triangle measure 5 cm and 12 cm, which of the following could be the length of the third side?

3. The longest side of a triangle is always opposite the   angle.

4. The sum of the lengths of any two sides of a triangle must be   than the length of the third side.

5. Consider a triangle with angle measures 30°, 70°, and 80°. List the sides in order from shortest to longest. Explain your reasoning.

6. If a triangle is equilateral, then all its angles are equal.

7. A triangle can have side lengths 3 cm, 4 cm, and 8 cm.

8. Draw a triangle where the side opposite the largest angle is clearly the longest side. Label the angles and sides.

9. A carpenter is building a triangular frame. Two of the boards are 10 feet and 15 feet long. What are the possible whole number lengths for the third board?