In this question, it is given that the diagonal of the board is 18 inches long and one side of the board is 12 inches long.
Let the other side is of length b inches .
Now we use pythagorean identity, which is

Here, a = 12 and c=18
Substituting these values, we will get

And the formula of perimeter is

Substituting the values of the two legs, we will get

Answer for the first question:

Answer for the second question:

160 cm because if I am correct, then two of the sides are labeled as 10 cm. Which means that they are both the same measurement.
Its 144. you just subtract the 121 from 265.
2 because it is the number being added to the zero intercept in the equation