Succeed with maths – Part 2

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

1.3 Four-sided shapes

Shapes that have four straight edges are known collectively as quadrilaterals. The most familiar of these are squares and rectangles. It might seem very obvious how these are defined but a rectangle (it’s not called an oblong in maths!) has four straight sides that are all at right-angles to each other, with opposite pairs of lines being the same length. A square is a special kind of rectangle, where all the sides are the same length. This means that in both shapes, opposite pairs of lines are also parallel. These are both shown in Figure 7 – lines of the same length have been marked with a single or double short perpendicular line.

Figure _unit7.1.7 Figure 7 A rectangle and a square

What if you have a four-sided shape where only one pair of lines is parallel? This is known as trapezium and an example is shown below in Figure 8. The parallel lines are marked with arrows.

Figure _unit7.1.8 Figure 8 A trapezium

If the quadrilateral, a four-sided shape, has two sets of parallel sides, it is called a parallelogram:

Figure _unit7.1.9 Figure 9 A parallelogram

Of course, this definition also means that squares and rectangles are parallelograms!

Now these more familiar shapes have been defined, it is useful to look at how to refer to specific sides or angles in a shape so that these can be clearly communicated to others. This is the subject of the next brief section.

SWMB_2

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, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 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 prospectus371