He needs to lay a piece of pipe that will run along the diagonal of the lawn . It means that we have to use pythagorean identity that is
[tex] a^2 +b^2 =c^2 [/tex]
Where a and b are the two legs or the two sides and c is the hypotenuse or the diagonal .
Here a= 15, b =8 and we need to find the value of c . Therefore we substitute the values of a and b and solve for c
[tex] 15^2 + 8^2 = c^2 [/tex]
[tex] 225 + 64 = c^2 [/tex]
[tex] 289 = c^2 [/tex]
Now we need to get rid of the square and for that, we take square root to both sides .
[tex] \sqrt{289} =c [/tex]
c=17
So the length of the pipe is 17 feet .
