(drawn with perimeter 1)

right triangle

edge lengths | ((sqrt(3) p)/(3 + sqrt(3)) | p/(3 + sqrt(3)) | (2 p)/(3 + sqrt(3)))≈(0.366025 p | 0.211325 p | 0.42265 p) area | p^2/(12 + 8 sqrt(3))≈0.0386751 p^2 interior angle sum | 180° = π rad≈3.142 rad (assuming perimeter p)