Find all triangles of which perimeter and area are numerically equal Find all triangles of which perimeter and area are numerically equal. I have got    solution for right angle triangles but not of others

The area is $A = \sqrt{s(s-a)(s-b)(s-c)}$, where $s$ is the semiperimeter. Thus we get
$$(a+b+c)^2 = \frac{a+b+c}{2}(\frac{a+b+c}{2} - a)(\frac{a+b+c}{2} - b)(\frac{a+b+c}{2} - c).$$
We can further simplify this to
$$16(a+b+c) = (-a+b+c)(a-b+c)(a+b-c).$$
Let $u = -a+b+c$, $v = a-b+c$, $w = a+b-c$. Then
$$16(u+v+w) = u v w.$$
In particular any $u,v$ such that $uv > 16$ give a solution for $w$:
$$w = \frac{16(u+v)}{uv-16}.$$
Now for such $u,v,w$ we have that $a = \frac{v+w}{2}$, $b = \frac{w+u}{2}$ and $c = \frac{u+v}{2}$ are the sides of a triangle whose area is equal to its perimeter.
