Which type of number is the number $\pi$ - rational or irrational?

Find three different irrational numbers lying between $\sqrt{3}$ and $\sqrt{5}$.

Recall,$\pi$ is defined as the ratio of the circumference (say $c$) of a circle to its diameter (say $d$). That is,$\pi = \frac{c}{d}$. This seems to contradict the fact that $\pi$ is irrational. How will you resolve this contradiction?

Are there two irrational numbers whose sum and product both are rational? Justify.

Represent $\sqrt{7.5}$ on the number line.

Represent $\sqrt{5}$ on the number line.