Question

1. what theorem is used to determine if the base angles of a triangle are congruent?

base angle theorem
isosceles triangle theorem
midsegment theorem
pythagorean theorem

Explanation:

The isosceles triangle theorem (also known as the base - angle theorem) states that if two sides of a triangle are congruent, then the angles opposite those sides (the base angles) are congruent. The base angle theorem is a specific name for this property related to the base angles of an isosceles triangle. The midsegment theorem is about the midsegment of a triangle (parallel to the third side and half its length), and the Pythagorean theorem is about the relationship between the sides of a right - triangle ($a^{2}+b^{2}=c^{2}$ for a right - triangle with legs $a,b$ and hypotenuse $c$). So the theorem used to determine if the base angles of a triangle are congruent is the isosceles triangle theorem (or base angle theorem, but among the options, isosceles triangle theorem is the standard name for this result).

Answer:

B. isosceles triangle theorem