Answer:
An angle bisector divides the angle measure into two equal parts. In triangle ABC, B is the point at which the angle lies.
Step-by-step explanation:
Picture segment BD drawn from point B of tri.ABC where it connects to segment AC, creating point D. Now picture E drawn on the newly created segment DC where it connects to point B and down to point C. Here's a drawing to better show this:
It's bisecting the bisected angle ABC. So, 140/2 = 70, and 70/2 = 35.