The indigenous "complementary" come from 2 Latin native "Complere" and also "Plere". "Complere" means "complete", conversely, "Plere" means "fill". For this reason "complementary" means "something the completes and brings perfection." and so space complementary angles, a pair of two angles that sum up come 90 degrees, developing a right angle.

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A part of bread is rectangular in shape, but when it is separated into 2 pieces by cutting follow me the diagonal, two appropriate triangles space formed, each with a pair of security angles. In this lesson, us will discover the human being of safety angles.

1.What are Complementary Angles?
2.Adjacent and also Non-Adjacent security Angles
3.How to uncover the enhance of one Angle?
4.Properties of security Angles
5.Complementary angles v/s Supplementary Angles
6.Complementary angle Theorem (with Illustration)
7.FAQs on safety Angles

What room Complementary Angles?

The complementary and supplementary the the 2 angles is made decision by the amount of your measurement. If the amount of the 2 angles is equal to the measure of a best angle then the pair of angle is said to be complementary angles.

Complementary angle Definition:

Two angle are said to it is in complementary angles if they include up to 90 degrees. In other words, when complementary angle are placed together, they kind a best angle (90 degrees). Angle 1 and angle 2 space complementary if the sum of both the angles is equal to 90 degrees (angle 1+ angle 2 = 90°) and thus, edge 1 and also angle 2 are referred to as complements of each other.

Complementary angles Example:

In the number given below, 60° + 30° = 90°. Hence, indigenous the "Definition of security Angles", these 2 angles space complementary. Every angle amongst the complementary angles is referred to as the "complement" of the various other angle. Here,

60° is the match of 30°30° is the match of 60°


Adjacent and Non-Adjacent security Angles

If the amount of 2 angles is equal to the measurement of a right angle then the pair of angle is recognized as the safety angle. There room two species of complementary angle in geometry as provided below:

Adjacent security AnglesNon-adjacent safety Angles

Adjacent complementary Angles: two complementary angles through a common vertex and also a typical arm are called adjacent complementary angles. In the number given below, ∠COB and also ∠AOB are surrounding angles together they have a usual vertex "O" and a common arm "OB". They also include up come 90 degrees, the is ∠COB + ∠AOB = 70°+20° = 90°. Thus, these two angles are surrounding complementary angles.


Non-adjacent safety Angles: 2 complementary angles that space NOT surrounding are said to it is in non-adjacent security angles. In the number given below, ∠ABC and ∠PQR space non-adjacent angles as lock neither have a usual vertex no one a typical arm. Also, they add up come 90 levels that is, ∠ABC + ∠PQR = 50° + 40° = 90°. Thus, these 2 angles space non-adjacent complementary angles. As soon as non-adjacent complementary angle are put together, they kind a ideal angle.


How come find match of one Angle?

We recognize that the amount of 2 complementary angles is 90 degrees and each of lock is said to it is in a "complement" of every other. Thus, the match of an edge is found by subtracting it indigenous 90 degrees. The match of is 90-x°. Let's find the complement of the angle 57°. The match of 57° is obtained by individually it native 90°. 90° - 57° = 33°. Thus, the complement of 57° angle is 33°.

Properties of complementary Angles

Now we have currently learned about the types of security angles. Let's have a look at some vital properties of security angles. The nature of complementary angles are given below.

Two angles are stated to be complementary if they include up come 90 degrees.Two complementary angles have the right to be either nearby or non-adjacent.Three or an ext angles can not be complementary even if their sum is 90 degrees.If two angles are complementary, every angle is referred to as "complement" or "complement angle" that the other angle.Two acute angles of a right-angled triangle are complementary.

Complementary angle v/s Supplementary Angles

The supplementary and also complementary angles are angles that exist in pairs, summing approximately 180 and 90 degrees, and also have many real-time applications, most usual being the crossroads. Let's have a look at the difference in between them.

The supplementary vs complementary angles table:

Supplementary AnglesComplementary Angles
A pair of edge are claimed to be supplementary if their amount is 180 degrees.A pair of edge are stated to it is in complementary if their amount is 90 degrees.
Supplement that an edge x° is (180 - x)°The enhance of an edge x° is (90 - x)°

Here is a brief trick because that you to know the difference between supplementary angles and complementary angles.

"S" is because that "Supplementary" and also "S" is for "Straight." Hence, you can remember that two "Supplementary" angles as soon as put together kind a "Straight" angle."C" is for "Complementary" and also "C" is for "Corner." Hence, you have the right to remember that two "Complementary" angles when put together type a "Corner (right)" angle.

Complementary angle Theorem (with Illustration)

If the amount of two angles is 90 degrees, then us say that they are complementary. Each of the enhance angles is acute and also positive. Let's examine the complementary edge theorem through its proof. The complementary edge theorem states, "If 2 angles room complementary to the same angle, then they are congruent to each other".

Proof of Complementary edge Theorem

We know that complementary angle exist in pairs and sum upto 90 degrees. Think about the complying with figure and prove the complementary edge theorem.


Let united state assume the ∠POQ is complementary come ∠AOP and also ∠BOQ.Now as per the an interpretation of complementary angles, ∠POQ + ∠AOP = 90° and ∠POQ + ∠BOQ =90° .From the above two equations, we have the right to say that "∠POQ + ∠AOP = ∠POQ + ∠BOQ".Now subtract '∠POQ' indigenous both sides, ∠AOP = ∠BOQHence, the theorem is proved.

☛Related Articles

Check out the following important articles to know an ext about safety angles.

Example 1:

Find the angle x in the adhering to figure.



In the given figure, x and also 62° room complementary together they kind a appropriate angle. Hence, their sum is 90°

x + 62° = 90°

x = 90° - 62°

x = 28°

Therefore, the angle 'x' is 28°.

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Example 3: discover the worth of x if the following two angles are complementary.



Since the offered two angles space complementary, their amount is 90°. This way x/2 + x/3 = 90°, 5x/6 = 90°, x = 90° × 6/5 = 108°

Therefore, the value of x is 108°

Example 4: 2 angles are complementary. The measure up of the larger angle is 5 degrees more than 4 times the measure up of the smaller sized angle. What is the measure up of the bigger angle in degrees?


Let united state assume the the two complementary angles are x (larger) and y (smaller). By the provided information, x = 4y + 5. Due to the fact that the 2 angles room complementary, their amount is 90°, x + y = 90°⇒ (4y + 5) + y = 90°⇒ x = 4y + 5⇒ 5y + 5 = 90°, 5y = 85°, y = 17°