GCSE Secondary Maths Age 13-17 - Geometry & Measures: Angles of Regular Shapes - Explained

The video tutorial explains how to solve a geometry problem involving a regular octagon and two identical pentagons. It breaks down the problem into manageable steps, focusing on calculating the interior angles of the polygons and using these to find the size of a specific angle, X. The tutorial emphasizes understanding the properties of regular polygons and provides a method to calculate interior angles, making the problem less intimidating and straightforward to solve.

What is a key characteristic of a regular octagon?

• All sides are different lengths.

• It has nine sides.

• All angles are different.

• All sides and angles are equal.

How do you calculate the interior angle of a regular octagon?

• Add 360 to 720.

• Subtract 180 from 1080.

• Multiply 540 by 8.

• Divide 1080 by 8.

What is the sum of the interior angles of a pentagon?

• 360 degrees

• 540 degrees

• 720 degrees

• 1080 degrees

How do you find the angle X in the isosceles triangle formed?

• Add 54 to 180.

• Subtract 54 from 180.

• Divide 180 by 54.

• Multiply 54 by 2.

What is the sum of the interior angles of a polygon with eight sides?

• 1260 degrees

• 1080 degrees

• 900 degrees

• 720 degrees