TRIANGLES TERMINOLOGIES

Triangle

Has 3 possible vertices

Vertex Angle

Angles opposite the base

Base Angles

Two angles adjacent to the base

Altitude

Line segment drawn from a vertex perpendicular to the opposite side

Median

Line segment connecting the midpoint of a side and the opposite vertex

Angle Bisector

Divides an angle of the triangle into two congruent angles and has endpoints on a vertex and the opposite side.

Perpendicular Bisector

A side of a triangle divides the side into two congruent segments and is perpendicular to the sideE

Euler line

line which contains orthocenter, centroid, and circumcenter of a triangle

Orthocenter

Not always in the interior of the triangle, In an obtuse, the 2 sides of the obtuse angle and the corresponding altitudes are extended to meet at a point outside the triangle. Is on the vertex of the triangle

Centroid

Known as the ‘Center Mass of the Triangle’. Unlike the orthocenter, it is always inside the triangle and for right, isosceles, and equilateral triangle, it is located 1/3 of the altitude of the mass.

Incenter

the center of the largest circle that can be inscribed in a triangle

Circumcenter

the center of the circle circumscribing a triangle. It is not always inside the triangle. The vertices of the triangle lie on the circle and are equidistant from the circumcenter.

Equilateral

Classification of triangles acc to sides - triangle w/ 3 congruent angles and sides. Each angle measures 60 degrees

Isosceles

Classification of Triangle acc to sides - a triangle w 2 congruent sides and 2 congruent angles

Scalene

Classification of triangle acc to sides - triangle w/ no congruent sides and no congruent angles

Right triangle

Classification of triangles acc to angles - a triangle w/ a right angle

Oblique triangle

Classification of triangles acc to angles - a triangle w/ no right angle

Acute Triangle

A triangle w/ 3 acute angles

Equiangular Triangle

triangle w/3 congruent angles. Each measures 60 degrees

Obtuse Triangle

A triangle w/ one obtuse angleC

Congruent Triangles

when 2 triangles have the same shape and size and can be made to coincide part by part.

Similar Triangles

Triangles with the same same but different size