Answer
$A = 8.4$
Work Step by Step
We can find an expression for the height of the triangle:
$\frac{h}{b} = sin~\phi$
$h = b~sin~\phi$
We can find the area of the triangle:
$A = \frac{1}{2}ah$
$A = \frac{1}{2}a~b~sin~\phi$
$A = \frac{1}{2}(4.3)(5.4)~sin~46^{\circ}$
$A = 8.4$
