Teaching mathematics
Teaching mathematics

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Teaching mathematics

2.1 Triangles

Triangles are the most basic of the polygons (a polygon is a straight-sided shape). They have three sides, the smallest number of sides it is possible to have. Triangles also make a rigid structure, as any engineer will know.

You will know the names of the triangles which have further properties in addition to having three sides (Figure 6).

Described image
Figure 6 Types of triangle

In addition, the isosceles right-angled triangle has a right angle, two equal sides, and two equal angles of 45⁰ each.

Acute-angled triangles have three angles all smaller than a right angle.

Obtuse-angled triangles have one angle that is bigger than a right angle.

TM_1

Take your learning further

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