Answer
Value of $\sin\theta$ will be $\leq 1$, for any angle $\theta$ in standard position as
$ \sin\theta$ = $\frac{x}{r}$
and $ x \leq r$
Work Step by Step
For any angle $\theta$ in standard position, let's consider any point P(x,y) on its terminal side.
Distance of P from origin, r= $\sqrt {x^{2} + y^{2}}$
Therefore $ r\geq x$
or $ x \leq r$
By definition I, we know that-
$ \sin\theta$ = $\frac{x}{r}$
as $ x \leq r$, Hence value of $\frac{x}{r} \leq 1$
or value of $\sin\theta$ will be $\leq 1$, for any angle $\theta$ in standard position.
