Different types of angles by Khan Academy.

Assuming that we have two angles; the first one DBA is 40o; the second one ABC is 50o. We know for sure that DBA + ABC = 90o.


With that being said any angles that when added up are equal to 90o are called complementary; lets keep in mind that there’s not limit of how many angles you need to make them complementary, you could even have 45 angles of 2o each!. Here are some easy examples:




Now that you have learned what a complementary angles is, let’s continue with our second type!


The logic for this is the same as finding the complementary; you need to find the angles that instead of adding up to 90, they add up to an equal of 180.

As the image above shows, you can have as many angles you want as long as when added together, the result is equal to 180; In the example given by Khan Academy, we have 120(MNO) + 60(XYZ)

Classification of Angles – Right, Straight, Acute or Obtuse

Angle sizeClassificationExamples
Less than 90Acute
90Right Angle
Between 90 & 180Obtuse Angle
180Straight Angle
Between 180 & 360Reflex Angle
360Full Turn
Pasted from Maths with Mum – Be your child’s best tutor to have it a better quality than the one they were providing.

Congruent Angles,up%20the%20angle%20is%20irrelevant.

Types of Angles

Corresponding Angles

Interior Angles

Alternate Interior Angles

There is obviously more stuff but for God’s sake I’m not going to try to explain everything, besides the Algebra version is way too easy as you only need to know how to get the sin, cos, tan, cot, csc, sec of angles; something which is easy after getting the first three.

Out of that, make sure to refresh your brain with some calculus exercises, there are a lot that can be found on Internet, also watch Khan Academy, that’s usually my web resource to go when it comes to Mathematics.

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