# The Triangle

- Author:
- fred farmer

To begin we will list definitions of what a triangle is and some of its characteristics.

- Triangle: geometric figure consisting of three points joined together by segments.
- Acute Triangle: no angle greater than 90 degrees
- Obtus triangle: one angle greater than 90 degrees
- Right triangle: a 90 degree angle
- Isosceles triangle: 2 equal sides, 2 equal angles
- Equilateral triangle: 3 equal sides, 3 angle of 60 degrees
- Height of a triangle: a line segment that starts at a vertices forming a right angle with the opposite side.
- Base of a triangle: The side of the triangle with which the height forms a right angle.

- The perimeter is the total length of the sides of a triangle. To find the perimeter you must add the length of all three sides of the triangle.
- The area the triangle on the other hand is the surface covered by the triangle. In order to find it, you need the value of the height and the base; Area=(height*base)/2

## Interactive triangle

Notice that when the angle at C or B is obtus (more than 90 degrees) the height at A lies outside of the triangle. This may cause certain difficulties when calculating the area of the triangle. Here is a tutorial video that will explain and help you to find the height and base of any triangle.