Pythagoras theorem
In order to find the hypotenuse of each triangle we are going to focus on the sides of one of them:
Since the figure in the center is a square then all its sides lenght is 10 feet:
Since the triangle is divided in halfs, then:
Now we can find its hypotenuse. We have the following triangle:
We know, by the Pythagoras Theorem, that:
Since,
13² = 169
then
13² = hypotenuse²
Then
13 = hypotenuse
Answer- the hypotenuse of each triangle is 13ft