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Geometry
Types of Triangles
A triangle has three sides and is made of straight lines. A
triangle may be classified by how many of its sides are of
equal length. Or, it may be classified by what kind of angles
it has.
triangle may be classified by how many of its sides are of
equal length. Or, it may be classified by what kind of angles
it has.
Types of Triangles by Length
In an equilateral triangle,
all three sides are the
same length.
all three sides are the
same length.
In an isosceles triangle, two
sides are the same length. An
isosceles triangle may be right,
obtuse, or acute
sides are the same length. An
isosceles triangle may be right,
obtuse, or acute
In a scalene triangle,
none of the sides are the
same length. A scalene
triangle may be right, obtuse,
or acute (see below).
none of the sides are the
same length. A scalene
triangle may be right, obtuse,
or acute (see below).
Types of Triangle by Angle - Acute, Obtuse, Right Triangle,
and Equiangular Triangle
and Equiangular Triangle
Right Triangle, one of the angles is a
right angle—an angle of 90 degrees. A
right triangle may be isosceles or
scalene.
right angle—an angle of 90 degrees. A
right triangle may be isosceles or
scalene.
Acute Triangle, has all its angles
measuring less than 90 degrees.
An acute triangle may be equilateral,
isosceles, or scalene.
measuring less than 90 degrees.
An acute triangle may be equilateral,
isosceles, or scalene.
Obtuse Triangle: Has an angle more
than 90°
than 90°
Equilateral, Isosceles and Scalene
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>Triangles < you are here
scalene
equilateral
equilateral
isosceles
isosceles
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Triangles are 3 sided polygons.
Triangles
video
An obtuse triangle may be
isosceles or scalene.
isosceles or scalene.
Obtuse Triangle
Right Triangles
Acute Triangle
Equilateral Triangle:
All the angles are equal, each one measures
60 degrees. An equiangular triangle is a kind
of acute triangle, and is always equilateral.
60 degrees. An equiangular triangle is a kind
of acute triangle, and is always equilateral.
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Equiangular Triangle
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A triangle has three sides and three angles.
The three angles always add to 180°
The three angles always add to 180°
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