# Triangle Angle Sum Theorem (V4)

- Author:
- Tim Brzezinski

- Topic:
- Angles

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?