From e99601d2639cfa48e1493568581f52a7e876a614 Mon Sep 17 00:00:00 2001 From: koreandude555 <43703574+koreandude555@users.noreply.github.com> Date: Wed, 12 Dec 2018 02:19:31 -0600 Subject: [PATCH] Added a method (#23954) --- .../mathematics/area-of-a-triangle/index.md | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/guide/english/mathematics/area-of-a-triangle/index.md b/guide/english/mathematics/area-of-a-triangle/index.md index ca2eebf0d5..0c8d40a819 100644 --- a/guide/english/mathematics/area-of-a-triangle/index.md +++ b/guide/english/mathematics/area-of-a-triangle/index.md @@ -5,7 +5,7 @@ title: Area of a Triangle ## Area of a Triangle -A triangle is a three sided, two dimensional polygon. There are two methods to determine the area. +A triangle is a three sided, two dimensional polygon. There are three methods to determine the area. ### Method 1 The area of a triangle can be calculated by multiplying 0.5 to the base length to the perpendicular height. @@ -27,6 +27,19 @@ Mathematically this is expressed as: Note that the formula expressed above uses sides a and b and angle C between them. These can be substituted for another other two sides and the angle between them. +### Method 3 +If only the length of the sides are known, we can use what is known as Heron's formula to find the area. + +![Triangle-3](https://github.com/uuykay/misc/blob/master/area-triangle-image-3.jpg) + +Mathematically this is expressed as: + +![Formula-3](https://wikimedia.org/api/rest_v1/media/math/render/svg/d138044bb9ed870dd9dc5c7c8a3c07ab1db1705d) + +Where s is half the perimeter, or + +![Formula-3.1](https://wikimedia.org/api/rest_v1/media/math/render/svg/08ed8a6e351198e0c4ca8d71fa2e2bc4171e9439) + ### Terminology