Complementary Angles

Complementary angles are a pair of angles whose measures add up to 90 degrees.

Complementary angles is a middle school-level concept. It is listed in the California State Standards for Grade 6.

Prerequisites

Angle:

An angle is a measure of the amount of rotation about the point of intersection of two lines or line segments that is required to bring one into correspondence with the other.

Classroom Articles on Plane Geometry

	Acute Angle	Midpoint
	Altitude	Obtuse Angle
	Area	Parallel
	Circle	Perimeter
	Circumference	Perpendicular
	Collinear	Pi
	Diameter	Plane Geometry
	Geometric Construction	Point
	Golden Ratio	Radius
	Golden Rectangle	Supplementary Angles
	Hypotenuse	Triangle Inequality

Classroom Articles on Geometry (Up to Middle School Level)

	Cone	Pentagon
	Congruent	Polygon
	Cube	Prism
	Cylinder	Pyramid
	Decagon	Quadrilateral
	Dodecagon	Rectangle
	Dodecahedron	Regular Polygon
	Equilateral Triangle	Right Triangle
	Hendecagon	Sphere
	Heptagon	Square
	Hexagon	Surface
	Icosahedron	Surface Area
	Isosceles Triangle	Tetrahedron
	Nonagon	Trapezoid
	Octagon	Triangle
	Octahedron	Volume
	Parallelogram