Example:Find Angle Measure in Quadrilateral
Explanation:
In Euclidean plane geometry, a quadrilateral is a polygon with four sides (or 'edges') and four vertices or corners. Sometimes, the term quadrangle is used, by analogy with triangle, and sometimes tetragon for consistency with pentagon (5sided), hexagon (6sided) and so on. The word quadrilateral is made of the words quad (meaning "four") and lateral (meaning "of sides").
The interior angles of a simple quadrilateral add
up to 360 degrees of arc. (Our solved
example in mathguru.com uses this concept)
Quadrilateral

Six different types of quadrilaterals

Edges and Vertices

4







http://en.wikipedia.org/wiki/Quadrilateral
Types
of angles


Here, a and b are supplementary angles.

Angles equal
to 1/2 turn (180° or two right angles) are called straight angles. (Our solved example in mathguru.com uses this concept)
Right angle
An angle equal to 1/4 turn
(90° or π/2 radians) is called a
right angle. (Our solved example in mathguru.com uses this concept)
Two
lines that form a right angle are said to be perpendicular or orthogonal

http://en.wikipedia.org/wiki/Angle
The above explanation is copied from
Wikipedia, the free encyclopedia and is remixed as allowed under the Creative
Commons Attribution ShareAlike 3.0 Unported License.