Geometry

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

# Try some yourself

## Question 1

Calculate all the angles at the centres of these objects.

• (a) Each of the four angles is 360° ÷ 4 = 90°.

• (b) The two upper angles are both 180° ÷ 2 = 90°, and the lower angle is 180°.

• (c) Each of the six angles is 360° ÷ 6 = 60°.

• (d) Each of the twenty angles is 360° ÷ 20 = 18°.

• (e) The acute angle between the hands is 360° ÷ 12 = 30°; the reflex angle is 360° − 30° = 330°.

• (f) Each of the three angles is 360° ÷ 3 = 120°.

MU120_4M7

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus