Similar triangles are the same shape but not the same size. Remember that if two triangles are both exactly the same shape, and exactly the same size, then they are identical and we say they’re “congruent.” In a pair of similar triangles, all three corresponding angle pairs are congruent and corresponding side pairs are proportional.
Read MoreThe isosceles triangle theorem says that if two sides of a triangle are congruent, then its base angles are congruent. The base angles are the angles that touch the non-congruent leg. If we know that a triangle has two congruent sides, then we know it’s isosceles, and if we know that two interior angles are congruent, then we know the triangle is isosceles.
Read MoreVertical angles are angles in opposite corners of intersecting lines. So vertical angles always share the same vertex, or corner point of the angle. They’re a special angle pair because their measures are always equal to one another, which means that vertical angles are congruent angles.
Read MoreIn this lesson we’ll look at the angles formed when a pair of parallel lines is crossed by another line, called a “transversal.” When transversals cross parallel lines, they form angles with special angle relationships.
Read More
