What is the Sum of the Interior and Exterior Angles- Help with IGCSE GCSE Maths

Follow Maths

Are you following me on Facebook yet? Follow the link, like me on Facebook and be the first one to receive important news and updates.

follow explaining maths on facebook and pass your next maths exam!

Sum of the Interior and Exterior Angles of a Polygon

what are interios angles exterior angles maths revision

In this section I will explain to you what Interior and Exterior Angles are and how to calculate them. Interior Angles are angles on the inside of the polygon while the Exterior Angle lies on the outside. You will learn that the sum the interior angles depends on the amount of sides the shape has. The sum of the Exterior Angles will always equal to 360 degrees regardless the shape! Study the following videos carefully during your maths revision to see why and prepare yourself for your IGCSE GCSE Maths exam.

Why are there 180 degrees in a Triangle and 360 degrees in a Quadrilateral

Perhaps you already know that a Triangle has 180 degrees and a quadrilateral 360 degrees. By the way, it is better to say the sum of the interior angles of a triangle equals to 180 degrees and the sum of the interior angles of a quadrilateral equals to 360 degrees (please click here to learn more about interior and exterior angles). But do you also know WHY the sum of the interior angles of a triangle equals to 180 degrees? Have a look at the next maths video and find out! It is an experiment which you can try yourself at home and you will see why the sum of the interior angles of a triangle equals to 180 degrees. Have fun and good luck!

How to find the total amount of degrees in a Polygon

In the next maths videos you will construct your own formula to calculate the sum of the interior angles for any polygon. The example questions will show you that if you take the amount of sides of the shape (n) and subtract it by two and then multiply that number by 180 degrees (the amount of degrees in a triangle) you will get the amount of degrees in that polygon. That formula will then look like this: (n - 2) x 180 degrees. Study the next activities and answer the example questions for your maths revision and prepare yourself for your IGCSE GCSE Maths exam!

The best way to learn and understand maths is by solving example questions. So check the following video during your maths revision and learn how to calculate the interior angles of a polygon.

What is the sum of the Exterior Angles of a Polygon

The following videos will explain to you what Exterior Angles are and how to calculate the Exterior Angle of a Polygon. You will notice that for every polygon the sum of the Exterior Angles will always equal to 360 degrees. So it does not matter if you have a triangle, quadrilateral, pentagon, heptagon or a decagon, the sum of the exterior angles will equal to 360 degree! Study the maths videos and discover for yourself. Answer the example question in the second video about exterior angles and regular polygons. You might get a similar question on your nest maths exam. Let me know on the forum of this website if you still don't understand interior and exterior angles. I will help you and answer your questions and make some maths video for you. Good luck and have fun!

Prepare yourself for your maths exam and study the following video during your maths revision. You will continue to learn what exterior angles are and how to calculate the size of an exterior angle of a regular hexagon.

Congratulations! You now understand what interior and exterior angles are. Continue with your maths revision and click the link below. Here I will explain what circle theorem are. You will learn to calculate angles in circles. A very important section as a preparation for your IGCSE GCSE Maths exam. I will see you there!

Explain Circle Theorems