Find the missing term in the following figure?

Taking square root of the numbers on the edges

$$\sqrt{9}=3$$

$$\sqrt{36}=6$$

$$\sqrt{64}=8$$

$$\sqrt{169}=13$$

Adding these and dividing by 5 we get

$$\dfrac{3+6+8+13}{5}=\dfrac{30}{5}=6$$

Similarly, for the second one we get

$$\sqrt{16}=4$$

$$\sqrt{49}=7$$

$$\sqrt{9}=3$$

$$\sqrt{36}=6$$

Adding these and dividing by 5 we get

$$\dfrac{4+7+3+6}{5}=\dfrac{20}{5}=4$$

Hence, for the last one we get

$$\sqrt{81}=9$$

$$\sqrt{100}=10$$

$$\sqrt{25}=5$$

$$\sqrt{121}=11$$

Adding these and dividing by 5 we get

$$\dfrac{9+10+5+11}{5}=\dfrac{35}{5}=7$$

Hence, the answer is 7.