An angle is formed where two straight lines meet. We measure them in degrees and there are360 degreesin a full circle.
We can use the following facts to work out angles we don't know:
1.Angles around a single point add up to 3600.
2.Angles on a straight line add up to 1800. So the missing angle below must be 400.
3. Vertically opposite angles are equal. (This is when two straightlinescross!).
4.Angles in a triangle add up to 1800. (See'Polygons').
5.Angles in a quadrilateral add up to 3600. (See'Polygons').
When a straight line crosses two parallel lines there are more angle factswe can look for and use!
1. Corresponding anglesare equal - these are angles in a letter 'F'.
2. Alternate angles…