This document defines and describes different types of triangles based on their side lengths and angles. It explains that a triangle can be equilateral, isosceles, or scalene depending on whether its sides are all equal, two sides are equal, or all sides are unequal. It also defines right, obtuse, and acute triangles based on whether they have one 90 degree angle, one angle over 90 degrees, or all angles under 90 degrees.

1. Mohammed Naveed
VI-c

2.  a plane figure with three straight sides and
three angles.

3.  There are three special names given to
triangles that tell how many sides (or angles)
are equal.
 Equilateral
 Isosceles
 Scalene

4.  In geometry, an equilateral triangle is a
triangle in which all three sides are equal. In
traditional or Euclidean geometry, equilateral
triangles are also equiangular; that is, all
three internal angles are also congruent to
each other and are each 60°.

5.  In geometry, an isosceles triangle is a triangle
that has two sides of equal length. Sometimes
it is specified as having two and only two
sides of equal length, and sometimes as
having at least two sides of equal length, the
latter version thus including the equilateral
triangle as a special case.

6.  A scalene triangle is a triangle that has three
unequal sides, such as those illustrated
above.

7. What is an angle ?
 the space (usually measured in degrees)
between two intersecting lines or surfaces at
or close to the point where they meet.
 "in any triangle, the longest side is opposite
the largest angle"

8.  Right Angled Triangle :
 Obtuse Angled Triangle
 Acute Angled Triangle

9.  Right angle triangle is a triangle with one of
its angle exactly equal to 90°.As shown in the
picture.

10.  Obtuse angle triangle is a triangle with one of
its angle greater than (>) 90°. As shown in
the picture

11.  Acute angle triangle is a triangle with all three
angle less than (<) 90°. As shown in the
picture