The angles formed by this are right angles as illustrated by the square corners.
Shown above is the case where the parallel lines are perfectly horizontal and a vertical line cuts down through them. A good way to imagine this is to think of train tracks the two tracks are always at the same distance from each other and never cross. This means that they will never form an angle between themselves and will always be the same distance away from each other. In geometry, a pair of lines are said to be parallel to each other if they are such that they will never cross even when extended for any length. Therefore, by the same reasoning we also know that angles a and b are equal. For any two angles that are opposite when two straight lines intersect (cross each other), their sizes are equal. We can also say that angles a and c are equal this is by a rule known as opposite angles.
#Example of parallel shapes in geometry full
Since the full angle of a circle is equal to 360˚ we know that a, b, c and d must add up to 360˚. However, we can use this knowledge to work out other angles that are connected to a straight line.įrom the above diagram, since we know that the bottom line is a straight line and that the angle for a straight line is 180˚, we can say that angles a and b must add to 180˚. This is a very useful property of straight lines that we can use for calculating unknown angles.Īnother use of straight lines for calculating angles is seen when we have two straight lines crossing and forming four angles, like below. The angle that is found on a straight line is 180˚. However, straight lines possess properties which are very useful when working with angles, something which we will look at next. This is because these angles will both just make a straight line. AcuteĬlearly, when an angle is exactly 180˚ or exactly 360˚ it does not fall into any of the above categories.
There are four main types of angles that we will look at. One of the basics of geometry is the use of angles to draw shapes. An angle, as you will probably already know, is made by two straight lines that are connected at their tips.
This is so that, when we get to later parts of the module, we can draw our own shapes. The basic ideas of geometry were founded many thousands of years ago in ancient times, but due to the real-world nature of geometry, they are as useful today as they were back then.įor this GCSE course, you will need to make use of a protractor, ruler and a pair of compasses. Geometry is a massive part of mathematics and deals with things like lines, angles and shapes.
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