Math10.com

Triangles, Triangle Classification

Equilateral Triangle

If the three sides of a triangle are the same size the triangle is equilateral triangle.

equilateral triangle properties:
1) All sides are equal.
2) Angles of every equilateral triangle are equal to 60°
3) Every altitude is also a median and bisector.
4) Every median is also an altitude and bisector.
5) Every bisector is also an altitude and median.
6) If the length of a side is a. Area of the equilateral triangle is ¹/₄a²√3
7) The altitudes, medians and the bisectors of a equilateral triangle is equal to ¹/₂a√3

Isosceles Triangle

If two of the sides of a triangle are the same size the triangle is isosceles triangle.

The altitude for the unequal side is also the corresponding bisector and median, but is wrong for the other two altitudes. It is also true that the median for the unequal sides is also bisector and altitude, and bisector between the two equal sides is altitude and median.

Right Triangle

A triangle with right angle(90°) is right triangle.

The longest side of a right triangle(it is opposite the right triangle) is hypothenuse and the two short sides are legs. The altitude for each leg equals the other leg.