Angles

Front

What is an angle?

Back

An angle is formed by two rays (sides) that share a common endpoint (vertex).

Front

What is the vertex of an angle?

Back

The vertex is the point where the two rays of an angle meet.

Front

What are the types of angles based on their measures?

Back

1. Acute angle: less than 90 degrees. 2. Right angle: exactly 90 degrees. 3. Obtuse angle: more than 90 degrees but less than 180 degrees.

Front

What is a right angle?

Back

A right angle measures exactly 90 degrees.

Front

What is an acute angle?

Back

An acute angle measures less than 90 degrees.

Front

What is an obtuse angle?

Back

An obtuse angle measures more than 90 degrees but less than 180 degrees.

Front

How do you find the measure of a missing angle in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees. Subtract the sum of the known angles from 180 to find the missing angle.

Front

If angle A measures 30 degrees and angle B measures 60 degrees, what is the measure of angle C in triangle ABC?

Back

Angle C measures 90 degrees (180 - 30 - 60 = 90).

Front

What is the sum of angles on a straight line?

Back

The sum of angles on a straight line is always 180 degrees.

Front

What is the measure of angle GEF if it is 15 degrees and angle DEG is a right angle?

Back

Angle DEF measures 105 degrees (90 - 15 = 75; 180 - 75 = 105).