Which kind of angle is formed when this angle is bisected?
That will depend entirely on the angle bisected which has not been given.
If a 60-degree angle is bisected and then each new angle is bisected what is the measure of the smallest angle formed?
Does the angle bisector of the vertex angle of an isosceles triangle divides the triangle into two congruent?
It depends on what is given. In general, one half of the bisected angle is proven to congruent to the other half. By the Definition of an Angle Bisector, the bisected angle can be proven bisected. ---- To show that two angles are congruent: One way to prove the two angles congruent is to show that their measures are equal. This can be done if there are numbers on the diagram. Use the Protractor Postulate…
The interior angle of a polygon is the angle formed by two adjacent sides of a polygon where the angle lies inside the area formed by the polygon. The exterior angle is that formed by one of these sides and the line formed by extending the other side. Consequently, External angle = 180 deg - Internal angle. Because they form supplementary angles, it does not matter which of the two sides you extend.