Why do Angles in a Triangle Add to 180 Degrees?
To investigate the sum of the angles in a triangle, we can begin by marking each angle with a different colour.
We can use this to find out what the angles in a triangle add up to.
If we move these angles so that they fit in next to each other, we can see that they rest on a straight line.
Angles on a straight line add up to 180°.
Therefore, angles in a triangle also add up to 180°.
You can test this at home by following these steps:
1) Cut out a triangle
2) Mark the outer angles
3) Cut these angles off
4) Place these marked angles together
You should be able to place these angles onto a straight line.
Angles in a triangle add up to 180°.
