CTET 2 Math and Science Dec 2019 Paper

Given, the perimeter of a triangle = 12 cm
i.e., a + b + c = 12 cm
we know that in any triangle, sum of any two sides is always greater than third side
∵ a + b + c = 12
∴ 3 + 4 + 5 = a + b + c
∴ a = 3, b = 4, c = 5
3 + 4 > 5 ⇒ a + b > c
4 + 5 > 3 ⇒ b + c > a
and 3 + 5 > 4 ⇒ a + c > b
Hence, there are 3 posible triangles.