Geography

Explanation

This is the formula for the area of a triangle

$A = \frac12 bh$

\(\frac12 bh\) means \(\frac12 \cdot b \cdot h\).  Substitute 405 for b and 200 for h

$= \frac12 \cdot 405 \cdot 200$

Write 405 and 200 as fractions

$= \frac12 \cdot \frac{405}{1} \cdot \frac{200}{1}$

Multiply the numerators.  Multiply the denominators.

$= \frac{1 \cdot 405 \cdot 200}{2 \cdot 1 \cdot 1}$

Factor 200 as 2 • 100.  Then remove the common factor of 2 from the numerator and denominator.

$\require{cancel} = \frac{1 \cdot 405 \cancel{2}^1 \cdot 100}{\cancel{2}_1 \cdot 1 \cdot 1}$

In the numerator, multiply: 405 • 100 = 40500

$= 40500$

The area of the state of Virginia is approximately 40,500 square miles.  This can be written as 40,500 mi²