# Why are square roots irrational?

First, not all square roots are irrational. For example, $\sqrt{9}$ has the perfectly rational solution of $3$
Before we go on, let's review what it means to have an irrational number - it has to be a value that goes on forever in decimal form and is not a pattern, like $\pi$. And since it has a never ending value that does not follow a pattern, it cannot be written as a fraction.
For example, $\frac{1}{3}$ equals $0.33333333$, but because it repeats we can write it a as fraction
Let's get back to your question. Some square roots, like $\sqrt{2}$ or sqrt(20 are irrational, since they cannot be simplified to a whole number like $\sqrt{25}$ can be. They go on forever without ever repeating, which means we can;t write it as a decimal without rounding and that we can't write it as a fraction for the same reason.