geometry

acute angle

an angle that measures less than 90 degrees

acute triangle

a triangle in which all 3 interior angles measure less than 90 degrees

altitude of a triangle

a perpendicular line segment drawn from a vertex to the line containing the opposite side.

angle bisector

a line or ray that divides an angle into two equal angles

line bisector

a line that divides a segment into two equal parts

centroid

point where the three medians meet / center point of a triangle.

circumcenter

center of a circle around a triangle

complementary angles

angles that add up to 90 degrees

congruent angles

angles that are equal

congruent segments

lines that are the same length

congruent triangles

triangles that are the same size and shape

equiangular triangle

a triangle with three equal angles

equilateral triangle

a triangle with three equal sides

incenter

the center point inside a triangle

isosceles triangle

a triangle with two equal sides

linear pair

two angles that form a straight line

median of a triangle

a line from a corner to the middle of the opposite side

midpoint of a line segment

the middle point of a line segment

perpendicular bisector of a segment

a line that cuts a segment in half at 90 degrees

an obtuse angle

an angle greater than 90 degrees

obtuse triangle

a triangle with one angle greater than 90 degrees