This document contains theorems and examples regarding isosceles and equilateral triangles. Theorem 4.7 states that if two sides of a triangle are congruent, then the angles opposite them are congruent. Theorem 4.8 is the converse of 4.7 - if two angles of a triangle are congruent, then the sides opposite them are congruent. The document then provides examples applying these theorems to find unknown side lengths and angle measures of various triangles. It also introduces the midsegment theorem, which states that the segment connecting the midpoints of two sides of a triangle is parallel to the third side and half its length, along with examples applying this theorem.