Area of a Triangle:
A triangle with a base of length B and a height of length H has an area of:
[tex]A=\frac{B\cdot H}{2}[/tex]
The base and the height must be perpendicular.
It's given a triangle with a base of B = 10 km and a height of H = 12 km. Note both dimensions are perpendicular, so we can calculate the area regardless of the other dimensions provided.
[tex]\begin{gathered} A=\frac{10km\cdot12km}{2} \\ A=60km^2 \end{gathered}[/tex]
