SAMBHAV MISHRA
Last Activity: 5 Years ago
It is based on permutation combination concepts.
Let A, B, C are angles of triangles.
we know, sum of all angles of triangle equal 180°.
so, A° + B° + C° = 180°
we know, according to triangle definition,
A, B , C ∉ {0°, 180°}
so, total number of triangles = ¹⁷⁹C₂
but we have to find number of triangles of different shapes
case 1 :- if A = B = C = 60°
it is only one possible .
case 2 :- if A = B ≠ C , B = C ≠ A, C = A ≠ B
if A = 178° then, B = C = 1°
if A = 176° then, B = C = 2°
..............
........................
if A = 1° then, B = C = 89°
means, number of solution = 89
but a solutions we have to remove when A = 60° then B = C = 60°
so, number of solution = 88
similarly , we can get 88 for A = B ≠ C an C = A ≠ B.
hence, total number of solution = 88 × 3
then, total number of solutions from here = 3 × 89 - 3 = 3 × 88 = 264
case 3 :- if A ≠ B ≠ C ,
then number of solutions = (¹⁷⁹C₂ - 264 -1)/3!
= 2611
now, total number of triangles of different shapes = 1 + 88 + 2611 = 2700
now, n/100 = 2700/100 = 27
