Explanation:
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with
vertices A, B, and C is denoted ABC.
Types
of triangles
By relative lengths of sides
Triangles can be classified according to the relative lengths of
their sides:
1. In an equilateral triangle all sides have the same length. An
equilateral triangle is also a regular
polygon with all angles measuring
60°. In
an isosceles triangle,
two sides are equal in length^{.} An
isosceles triangle also has two angles of the same measure; namely, the angles opposite to the two sides of the same
length; this fact is the content of the Isosceles
triangle theorem. Some mathematicians define an isosceles triangle to have
exactly two equal sides, whereas others define an isosceles triangle as one
with at least two equal sides. The latter definition
would make all equilateral triangles isosceles triangles. The 45-45-90 Right
Triangle, which appears in the Tetrakis
square tiling, is isosceles.
2. In a scalene triangle, all sides are
unequal. The three angles are
also all different in measure. Some (but not all) scalene triangles are also
right triangles.
http://en.wikipedia.org/wiki/Triangle
Right triangle
Right triangle
A right
triangle (American English)
or right-angled triangle (British English) is a triangle in which one angle is a right
angle (that is, a 90 degree angle). (Our solved example in mathguru.com uses
this concept)
http://en.wikipedia.org/wiki/Right_triangle
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.
(Our solved example in mathguru.com also uses the below concept.
This is our own explanation, it is not taken from Wikipedia.)
The sum of all the angles of a Triangle
is 180(Angle Sum
Property of a Triangle)