90 Degree Angle - Measurement, Construction, Examples - Cuemath

90 Degree Angle

A 90-degree angle is a right angle. If the value of the angle between the horizontal and vertical lines is exactly equal to 90 degrees, then the angle is called a 90-degree angle. Some of the real-life examples of a 90-degree angle are the angle between the hands of a clock at 3 o'clock or 9 o'clock, angles between two adjacent edges of a rectangular door or window, etc.

1.	What is a 90 Degree Angle?
2.	How to Draw 90 Degree Angle?
3.	FAQs on 90 Degree Angle

What is 90 Degree Angle?

A 90-degree angle is a right angle and it is exactly half of a straight angle. It always corresponds to a quarter turn. Rectangle and square are the basic geometric shapes that have a measurement of all four angles as 90 degrees. When two lines intersect each other and the angle between them is 90 degrees then the lines are said to be perpendicular.

Look the image given below shows what a 90-degree angle looks like. Angle DAB is a 90-degree angle. It is formed by a ray AB with its perpendicular ray DA.

How to Draw 90 Degree Angle?

The 90-degree angle can be drawn by using a protractor and compass.

Constructing 90-Degree Angle Using a Protractor

Follow the given steps to construct a 90-degree angle using a protractor:

• Step 1: Draw a ray OA.
• Step 2: Place the center of the protractor at point O.
• Step 3: In the outer or the inner circle of the protractor, look for 90° reading and with a pencil mark a dot and name it C.
• Step 4: Join O and C. You will observe the vertical line OC and horizontal line OA are perpendicular to each other and meeting at a common point O. Thus, ∠AOC = 90-degree angle.

Constructing 90-Degree Angle Using a Compass

Follow the given steps to construct a 90-degree angle using a compass.

• Step 1: Draw a ray AB with help of a ruler.
• Step 2: Put the tip of the compass at A and draw an arc that cuts ray AB and mark that cut point as C.
• Step 3: Put the compass tip at C and draw an arc of radius AC that cuts the arc drawn in step 2 and mark that cut point as D.
• Step 4: With the compass tip at D, draw an arc of radius AC using a compass to cut the arc drawn in Step 2 and mark that cut point as E.
• Step 5: With the tip at D, draw another arc using the same radius AC between points D and E.
• Step 6: With the tip at E, draw another arc using the same radius AC to cut the arc drawn in step 5 and mark that cut point as F.
• Step 7: Join F and A. The angle FAB is a 90-degree angle.

Important Notes:

• The 90-degree angle is also called a right angle.
• A 90-degree angle can be constructed with a protractor or a compass.

► Related Articles

Check out these interesting articles to learn more about the 90-degree angle and its related topics.

• 60 Degree Angle
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• 270 Degree Angle
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