Altitude

An altitude of a triangle is a line segment from one of its vertices which meets the opposite side at a right angle.

Altitude is a middle school-level concept. It is listed in the California State Standards for Grade 7.

Prerequisites

A triangle is a three-sided (and three-angled) polygon.

Classroom Articles on Plane Geometry

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

Classroom Articles on Geometry (Up to Middle School Level)

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