#### Answer

H

#### Work Step by Step

The area of a triangle is $\frac{1}{2}bh$, where b is the length of the base and h is the height.
$\frac{1}{2}bh\longrightarrow$ substitute the given values
=$\frac{1}{2}(2.1\times10^3)(4.2\times10^2)\longrightarrow$ multiply the digit terms and add the exponents.
=$\frac{1}{2}(8.82\times10^5)\longrightarrow$ multiply
=$4.41\times10^5$