# Thread: Geometry, perimeter, area of a triangle

1. ## Geometry, perimeter, area of a triangle

* *
***** 20
****** *
* ****** *
* **********
* ********** *
* ************* *
*******************
16

please show me how to find the perimter and area of above triangle. thanks.
suwanee

2. Originally Posted by Suwanee
* *
***** 20
****** *
* ****** *
* **********
* ********** *
* ************* *
*******************
16

please show me how to find the perimter and area of above triangle. thanks.
suwanee
Hello,

I assume that your triangle is a right triangle.

1. Perimeter. You know already the length of 2 sides. Use Pythagorean theorem to find the 3rd side:
$\displaystyle s=\sqrt{20^2 - 16^2}=12$

Thus the perimeter is p = 20 + 16 + 12 = 48

2. Area: The area of a right triangle is the half of a rectangle. The sides of the rectangle are the legs of the right angle. Thus
$\displaystyle A_{rectangle}=16 \cdot 12 = 192$
Therefore the area of the triangle is 96 square units.

3. ## thanks!!!

Thank you Earboth!!!!!