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Expansion of Area of Triangles (#29909) 

Fixed a small type-o and added information about the area of obtuse triangles.
pull/31773/head^2
joesvetz 2019-03-14 09:43:28 -07:00 committed by The Coding Aviator
parent e4e9ee88d1
commit 052a0dd1b4
1 changed files with 10 additions and 2 deletions
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guide/english/mathematics/area-of-triangles/index.md
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@ -10,11 +10,11 @@ The area of a triangle can be calculated by multiplying one half by the base * h
For example, if you have a triangle that is 3cm on the base and 4cm in height, then you can work out the area:
Areaa= .5 * 3 * 4 = 6cm²
Area = .5 * 3 * 4 = 6cm²
#### Terminology
* Base (b) - The length of one side of the triangle.
* Base (b) - The length of one side of the triangle (note: the side chosen for the base must always have angles of 90 degrees or less on both ends)
* Height (h) - The length of a line perpendicular with the base to the opposite point of the triangle.
#### Formula
@ -26,6 +26,14 @@ For example in the image above,
Area = 0.5 * a * h
#### Important information about Obtuse Triangles
An obtuse triangle is one that has an internal angle of more than 90 degrees, like the one pictured below:
<img src="http://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Obtuse_Triangle.svg/1024px-Obtuse_Triangle.svg.png" width="400">
In this case, the base must be side 'BC' and not 'AB' or 'CA' (the height would be a perpendicular line from the base to point 'A'). If the measurement of the height is not known, it would have to be measured, or it would need to be calculated using trigonometry.
### More Information
* [Area of Triangles](http://www.onlinemathlearning.com/area-triangle.html)