Five-Minute Check (over Lesson 13–2)

Main Idea and Vocabulary

Key Concept: Classify Triangles by Sides

Example 1:Identify Sides

Key Concept: Classify Triangles by Angles

Example 2:Identify Angles

Identify Angles

• I will identify characteristics of triangles.

• isosceles triangle

• equilateral triangle

• scalene triangle

• acute triangle

• right triangle

• obtuse triangle

Identify Sides

Measure to find the number of congruent sides. Then state whether any of the sides appear to be perpendicular. Write yes or no.

Answer: All of the sides of the triangle have the same length. So, all 3 sides are congruent.

No; none of the sides of the triangle appear to be perpendicular.

1. A

2. B

3. C

4. D0% 0%0%0%

A. 2; yes

B. 2; no

C. none; yes

D. none; no

Measure to find the number of congruent sides. Then state whether any of the sides appear to be perpendicular.

Identify Angles

Triangles form the dome of Spaceship Earth at Epcot Center in Florida. Identify the kind of angles in the triangles.

Answer: There are two acute angles and one obtuse angle.

Draw a triangle like the ones in the photo.

1. A

2. B

3. C

4. D0% 0%0%0%

A. 1 right, 2 acute

B. 1 right, 2 obtuse

C. 3 right

D. 2 acute, 1 obtuse

Identify the kind of angles in the triangles.

End of the Lesson

Five-Minute Check (over Lesson 13–2)

Image Bank

Math Tool Chest

Identify Angles

1. A

2. B

3. C

4. D

0% 0%0%0%

(over Lesson 13–2)

Solve. Use the logical reasoning strategy. Andrea, Gaby, Mateo, and Akil raced in the hundred meter dash. Use the following clues to determine the order of the runners at the finish line. 1. Mateo could not catch up with Gaby or Akil.2. Andrea did not come in second or third.3. Gaby pulled ahead of Akil right at the finish line to take

first place.

A. Gaby–first, Akil–second, Mateo–third, Andrea–fourth

B. Akil–first, Mateo–second, Gaby–third, Andrea–fourth

C. Andrea–first, Gaby–second, Mateo–third, Akil–fourth

D. Gaby–first, Akil–second, Andrea–third, Mateo–fourth