Is anyone able to give a step by step process to this?

The value of y is 3 cm.

Step-by-step explanation:

Given,

Perimeter of triangle =

Solution,

Lets redraw the triangle with nomenclature ABC, given in the attachment.

∴P(ΔABC) = 29 cm  (P stands for perimeter)

Length of AB =

Length of BC =

Length of CA =

Now, we all know that the perimeter of a triangle is sum of all the three sides of triangle.

P(ΔABC) = Length of AB+Length of BC+Length of CA

On substituting the values, we get;

Length of AB =

Length of BC =

Length of CA =

Hence the value of y is 3 cm.