Question: what was the formula to find the perimeter of a triangle?
Answer: In the given triangle, a, b and c are the sides of the triangle. Perimeter of a triangle.
Perimeter of triangle = a + b + c. ... 
Here, sides of the triangle are AB = 3 cm, BC = 4 cm and AC = 3 cm. ... 
Perimeter of an isosceles triangle = a + b + c. ... 
Perimeter of an equilateral triangle = a + b + c.