Friday, 19 December 2014

Perfect Triangle





Perfect Triangles are defined as the triangles having side lengths that are integers and for which the area and perimeter of the triangle are equal.
Imagine a triangle with side lengths of x + y, y + z, and x + z, the problem can be narrowed down algebraically. For this triangle, the perimeter  is equal to 2 (x +y+ z)

 And the semi perimeter ‘s’ =  (x +y+ z) 

Equating area with the semi perimeter we get:
√[s{s-(x +y)}{s-(y +z )} {s-( z+x)}] = 2 (x +y+ z)


√ [(x +y+ z){(x +y+ z) -(x +y)}{(x +y+ z) -(y+z )}{ (x +y+ z) -(z+x)}]= 2(x +y+ z)
Now solving the above equation , we get the following equation:

xyz = 4(x+y+z)

We have already solved the above equation  in the previous post on Diophantine Equation:

The solutions to the above equation are as below:

x
y
z
x+y
Side 1 of the Triangle
y+z
Side 2 of the Triangle
z+x
Side 3 of the Triangle
24
5
1
29
6
25
14
6
1
20
7
15
9
8
1
17
9
10
10
3
2
13
5
12
6
4
2
10
6
8

Thus there are only five Perfect Triangles for which The Perimeter and the area are same numerically as given in the above table.