Triangles: concepts, properties and types

Triangles

represent

are

divided into

Simpler ways

of

Polygons

Three sides

of

Three segments

also

that are

Linked end to end

that form

Three internal angles

Three vertices

that

Extended

form

Three external angles

are

Equal

to the

Sum

of the

Non-adjacent interior angles

together

Add up 180˚

are

Points where they coincide

constitute

The area

Is equal to

(base × height)/2

According to internal angles

special cases

According to the length of its sides

Acute triangle

Right triangle

Obtuse triangle

has

3 angles < 90°

has

1 angles = 90°

has

1 angle > 90°

Equilateral acute triangle

has

3 angles < 90°

3 sides =

Acute isosceles triangle

has

3 angles < 90°

2 sides = and 1 ≠

Scalene acute triangle

has

3 angles < 90°

3 sides ≠

Isosceles right triangle

has

1 angles = 90°

2 sides = and 1 ≠

Scalene right triangle

has

1 angles = 90°

3 sides ≠

Isosceles obtuse triangle

has

1 angle > 90°

2 sides = and 1 ≠

has

1 angle > 90°

3 sides ≠

Equilateral triangle

Isosceles triangle

Scalene triangle

has

3 sides =

has

2 sides = and 1 ≠

has

3 sides ≠

in which

The largest

is the

Opposite of the largest angle

Scalene obtuse triangle