How do you measure an angle


What is an angle? How do you measure an angle?

Learn how to identify right, acute and obtuse angles.

Learn FREE with videos and interactive exercises

The different types of angles

Let's start with the right angle. Two perpendicular half lines form a right angle. This angle is important because it allows us to name the other angles. A right angle is an angle of 90 degrees.

An angle smaller than a right angle is called acute angle.

An angle larger than a right angle is called obtuse angle.

When two half lines are on the same line, they form a straight angle. A straight angle is 180 degrees and it's the double of a right angle.

When the two arms of the angle coincide, you can see an internal angle and an external angle:

  • a zero angle is 0 degrees;
  • full angle is 360 degrees.

What is an angle?

What is an angle?

The parts of an angle

The parts of an angle