If the coordinates of $P$ and $Q$ are $( -2,\ 0)$ and $( -2,\ 7)$, then find $PQ$?

Given: The coordinates of $P$ and $Q$ are $( -2,\ 0)$ and $( -2,\ 7)$.

To do: To find $PQ$.

Solution:

Here, $x_1=-2,\ y_1=0,\ x_2=-2,\ y_2=7$

On using the distance formula, 

$PQ=\sqrt{( -2-( -2))^2+( 7-0)^2}$

$\Rightarrow PQ=\sqrt{0+49}$

$\Rightarrow PQ=\sqrt{49}$

$\Rightarrow PQ=7$

Therefore, distance $PQ=7\ unit$