Answer:
![√(18)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/wokv8lxn85g7ww9xdw1s8zy259jpo1iasj.png)
Explanation:
you need to use Pythagoras theorem
+
=
![c^(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/k35u7m6yuyioehiuxbng19npestgihit5x.png)
c is the hypotenuse. the longest side (ab)
a and b are the other two side lengths squared (bc,ca)
the length of both a and b are 3 squares long
is 9
you add the square of both sides together to get 18 this is
![c^(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/k35u7m6yuyioehiuxbng19npestgihit5x.png)
you need to square root that to get the answer
![√(18)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/wokv8lxn85g7ww9xdw1s8zy259jpo1iasj.png)