Exploring Angles and Symmetry

Identify the line of symmetry for the given figure: a square.

How many lines of symmetry does a square have?

Which of the following triangles is an acute triangle?

• A triangle with angles measuring 90°, 45°, and 45°

• A triangle with angles measuring 60°, 60°, and 60°

• A triangle with angles measuring 120°, 30°, and 30°

• A triangle with angles measuring 90°, 60°, and 30°

Using a protractor, what is the approximate measure of an angle that looks like a right angle?

• 30°

• 60°

• 90°

• 120°

Draw an angle that measures 45°.

If one angle measures 30° and the other angle measures 60°, what is the measure of the unknown angle formed by these two adjacent angles?

Identify the line of symmetry for the given figure: an equilateral triangle.

How many lines of symmetry did you make?

Which of the following triangles is an obtuse triangle?

• A triangle with angles measuring 90°, 45°, and 45°

• A triangle with angles measuring 60°, 60°, and 60°

• A triangle with angles measuring 120°, 30°, and 30°

• A triangle with angles measuring 90°, 60°, and 30°

Using a protractor, what is the approximate measure of an angle that looks like an acute angle?

• 30°

• 60°

• 90°

• 120°

Draw an angle that measures 120°.