The second side of a triangle is 11 more meters than the first side. The third side is twice more than the first side. If the perimeter of the triangle is 63 meters, find the length of the second side.

P = 63

P = a + b + c (these are the sides of our triangle)

63 = a + b + c

b = a + 11

c = 2a

We can substitute these values in terms of a in our earlier equation.

63 = a + a + 11 + 2a

Combine like terms ...

63 = 4a + 11

Subtract the 11 ...

52 = 4a

Divide by 4 ...

a = 13.

We can then use this to find the second side.

b = a + 11

b = 13 + 11

b = 24