Right Angle – Definition, Solved Examples, Facts, FAQs

In geometry, when two rays meet each other at a common point, they form an angle. The point of meeting of the two rays is known as the vertex.

Angles are measured in degrees (symbol: °)

Some common types of angles are acute angles, right angles, and obtuse angles.

Right angle 

When two straight lines intersect each other at 90˚ or are perpendicular to each other at the intersection, they form the right angle. A right angle is represented by the symbol ∟.

The given image shows various formations of the right angle.

We can find the right angles in shapes.

A square or rectangle has four corners with right angles.

Examples of right angles are all around us. We can see right angles in the corners of a room, book, cube, windows and at several other places.

A vertical and a horizontal line makes the most common right angles. However, diagonal lines intersecting each other also form right angles. If you draw the diagonals of a square, a rhombus or a kite, the angle at the intersection is 90 degrees and is, therefore, a right angle.

How to Draw a Right Angle Using A Protractor?

1. Start by drawing a horizontal line.

2. Now place the protractor on the horizontal line.

3. Measure 90˚ and mark it with a point.

4. Now using a scale, draw a straight line from this point to the horizontal line.

Fun Facts 

1. All right angles are the same.
2. All right angles correspond to a quarter of a complete turn.
3. All triangles with one angle right are called right-angled triangles.

Solved Examples on Right Angle

1. Find the number of right angles in the figure shown below. 

Solution: The above figure is a rectangle. The number of right angles in the above figure is 4. Each side in the figure meets the adjacent side at 90°. 

2. If the two lines PQ and RS are perpendicular, what is the measure of ∠SOT?

Solution:

              Since, line PQ ⟂ line RS, m∠SOQ=90°

Moreover, m∠SOQ=m∠QOT+m∠SOT

90°=30°+m∠SOT

Therefore, m∠SOT=90°-30°=60°

3. How many right angles are there in the given figure?

Solution:

The given figure shows 3 right angles and 2 obtuse angles.

Practice Problems on Right Angle

Frequently Asked Questions on Right Angle