Question

Jon would like to create a triangle below, but he needs exact dimensions. If the traingle given has the same perimeter as a square with a side length of 9, what is the value of y?

Answer 1

For this case we know that the perimeter is given by:

$P=y+9+2y+4y-1$

And if we solve the algebra we got:

$P=7y+8$

And we know that the perimeter is equal to the perimeter of a square of 9 of lenght and we know that the perimeter is:

$P=4x=4\cdot9=36$

We can set up the perimeter equal to this number we got:

$36=7y+8$

Now we can solve for y we got:

$y=\frac{36-8}{7}=\frac{28}{7}=4$