Question

rectangular field 450 meters long & 400 meters wide. what is the area of the field in square kilometers?

Answer 1

Given: A rectangular field with the dimension below:

$\begin{gathered} l=\text{length}=450m \\ w=\text{wide}=400m \end{gathered}$

To Determine: The area of the field in square kilometers

To find the area in square kilometers, first convert the dimension into kilometer.

$\begin{gathered} 1000m=1\operatorname{km} \\ xm=x\times\frac{1}{1000}km \\ l=450m=450\times\frac{1}{1000}km \\ l=0.45\operatorname{km} \end{gathered}$$\begin{gathered} w=400m=400\times\frac{1}{1000}km \\ w=0.4\operatorname{km} \end{gathered}$

The area of a rectangle is given by the formula is

$A_{\text{RECTANGLE}}=\text{length}\times width$

Since the field is a rectangle, then the area of the field would be

$\begin{gathered} A_{\text{RECTANGULAR FIELD}}=length\times width \\ A_{\text{RECTANGULAR FIELD}}=0.45\operatorname{km}\times0.4\operatorname{km} \\ A_{\text{RECTANGULAR FIELD}}=0.18\operatorname{km}^2 \end{gathered}$

Hence, the area of the rectangular field is 0.18km²