Triangle Angle Sum Theorem
In the applet below, note the triangle and its 3 large white vertices.
You can move the vertices anywhere you'd like at any time.
The pink slider controls the size of the (soon-to-appear) pink angle.
Interact with this resource for a few minutes. As you do, be sure to move the vertices of the triangle around each time before re-sliding the slider.
Please answer the question that follows.
1.
What can we conclude about the SUM of the measures of the pink angle, blue angle, and green angle (i.e. the 3 interior angles) of this triangle?