This question is from Motlanelo from Modubung High School.:
How do you calculate angles with reasons that have the value x, y and z.
There are 6 important rules to use when you are doing geometry:
- Remember vertically opposite angles are equal to each this other. This means that when two (or more lines) create an x the angles in the opposite corners are equal to each other.
- Angles on a straight line add up to 180 degrees, and angles inside a triangle also add up to 180 degrees.
- Angles around a point (that is, if you can draw a full circle around one line’s end) add up to 360 degrees.
- Parallel lines are very important and have 3 things to always be on the look out for. The first is corresponding angles. The angles that make an F shape with your parallel lines. These angles are equal.
- When parallel lines make an N or Z shape, these alternating angles are also equal.
- When parallel lines make a U shape, the co-interior angles (the inner parts of the U) add up to 180 degrees.
You need to learn these rules and then you need to practice. Use a different colour pen to highlight the lines that are parallel to each other. See if you can see the different shapes – the FUN, X and triangles, straight lines and angles around a point.
Also remember to create two columns. One for your statement (what you believe is true) and the second one for your reason (why you believe it is true). Statements also count marks so be sure to right them down.
The more you practice, the easier it will become to answer these questions because it will become easier and easier to see the different shapes.
Good luck 🙂