### Triangle

Triangle

Welcome visitors..
In this post, we will explain about triangle. The following is the definition of a triangle.

One of the basic shapes in geometry is a polygon with three ends and three vertices.

The formula for the perimeter of a triangle
Given a triangle with sides $a$, $b$, and $c$. Then the perimeter of the triangle is $k=a+b+c$.

Types of triangles
* Any triangle
* Right triangle
* Isosceles triangle
* equilateral triangle
Any Triangle is a triangle whose three sides are different lengths.
Right Triangle is a triangle in which one angle is a right angle ($\displaystyle \frac{1}{2} \pi$ radians).
Isosceles Triangle is a triangle with two sides the same length.
equilateral Triangle is a triangle whose all sides are the same length.

The formula for the area of ​​a triangle
$$L=\sqrt{s(s-a)(s-b)(s-c)}$$ or $$L=\frac{1}{2}ab.\text{sin }C$$ or $$L=\frac{1}{2}ac.\text{sin }B$$ or $$L=\frac{1}{2}bc.\text{sin }A$$ Where:
$L$: area of triangle.
$a,~b,~c$: Side length of triangle.
$s=(a+b+c)/2$.
$\text{sin }A$: The sin value of the angle opposite the side $a$.
$\text{sin }B$: The sin value of the angle opposite the side $b$.
$\text{sin }C$: The sin value of the angle opposite the side $c$.
Example:
Prove that the area of ​​a right angled triangle is half the product of the two sides of the right angled triangle. Solution:
From nature $\displaystyle L=\frac{1}{2}ab.\text{sin }C$, we take the value $\displaystyle C=\frac{1}{2} \pi$ so that $$\text{sin }\frac{1}{2} \pi=1$$ $$L=\frac{1}{2}ab$$ (proven).

This is an explanation of the Triangle. Bye and thank you.