Fun with Angles on Day Five

Let's learn about TRIANGLES...

In a triangle, the three angles always add to 180°:

A + B + C = 180°

One of our problems that we had to solve today was on angles in a triangle. We were all given a piece of paper and was asked to cut it into triangles. Upon cutting, the question that was asked was how do you that all the angles add up to 180°??

There were several ways that were discussed among my group, one of it being Lily Wei's method:

4 + 6  and 1 + 3 is 90 degrees respectively.
1 = 2
2 + 5 + 7 = 360 degrees - ( 1+ 6 + 4 + 3)
Which is 360 degrees minus 2 (90 degrees) = 180 degrees!!

Another method that i thought of was to fold the triangle in the following manner and you will see that it works out to be 180° for each of the four triangles. 

A course mate of mine provided the following method: When you cut away the corners and place the cut pieces in a straight line, it forms half a circle. As a full circle is 360°, half a circle will be 180°.

Are you able to find more ways? Share it with me if you find one :)