GCSE Secondary Maths Age 13-17 - Geometry & Measures: Angles in Polygons - Explained

The video tutorial explains how to solve a geometry problem involving a pentagon. It starts by identifying the problem and calculating the total degrees in a pentagon. The tutorial then demonstrates how to find unknown angles using given angles and the total degrees. It further explains the use of ratios to determine specific angle sizes, emphasizing the importance of understanding the relationship between angles. The tutorial concludes with a discussion on the marks awarded for each step and key points to remember for exams.

What is the total number of degrees inside a pentagon?

• 720 degrees

• 540 degrees

• 180 degrees

• 360 degrees

If you know three angles in a pentagon are 125, 115, and 90 degrees, what is the sum of the remaining two angles?

• 210 degrees

• 240 degrees

• 150 degrees

• 180 degrees

In the given problem, what is the relationship between angle C and angle B?

• Angle C is twice angle B

• Angle C is three times angle B

• Angle C is half of angle B

• Angle C is equal to angle B

How do you calculate the size of angle C if angle C is twice angle B and their sum is 210 degrees?

• Divide 210 by 3

• Multiply 210 by 2

• Subtract 70 from 210

• Divide 210 by 2

What is the size of angle C in the pentagon problem?

• 90 degrees

• 210 degrees

• 140 degrees

• 70 degrees