Note that, \(\displaystyle{\csc{\theta}}=\) \(\frac{\text{Hypotenuse}}{\text{Opposide side}}\)

So \(\text{Hypotenuse}=21\) and \(\text{Opposite side}=5\).

Use Pythagorean theorem to find adjacent side as follows.

Adjacent side \(\displaystyle=\sqrt{{{21}^{{2}}-{5}^{{2}}}}\)

\(\displaystyle=\sqrt{{{441}-{25}}}\)

\(\displaystyle=\sqrt{{416}}\)

Sketch a right triangle for given trigonometric function.

Find the other five trigonometric function as follows.

\(\displaystyle{\sin{\theta}}=\) \(\frac{\text{Opposide side}}{\text{Hypotenuse}}\) \(\displaystyle=\frac{{5}}{{21}}\)

\(\displaystyle{\cos{\theta}}=\) \(\frac{\text{Adjacent side}}{\text{Hypotenuse}}\) \(\displaystyle=\frac{\sqrt{{416}}}{{21}}\)

\(\displaystyle{\tan{\theta}}=\) \(\frac{\text{Opposide side}}{\text{Adjacent side}}\) \(\displaystyle=\frac{{5}}{\sqrt{{416}}}\)

\(\displaystyle{\sec{\theta}}=\) \(\frac{\text{Hypotenuse}}{\text{Adjacent side}}\) \(\displaystyle=\frac{{21}}{\sqrt{{416}}}\)

\(\displaystyle{\cot{\theta}}=\) \(\frac{\text{Adjacent side}}{\text{Opposide side}}\) \(\displaystyle=\frac{\sqrt{{416}}}{{5}}\)