Can someone please help me with the formula for the area of a triangle?

Mar 15, 2018

$A = \frac{1}{2} a b \sin C$

Explanation:

This is simply a case of learning the correct formula for the area of a triangle.

You need to have the combination of three facts as
'Two sides and the included angle,"

Angle $C$ lies between sides $a \mathmr{and} b$ and is therefore the included angle.

The correct formula is

$A = \frac{1}{2} a b \sin C$ which is the last option offered,

Mar 15, 2018

$A = \frac{1}{2} \cdot {h}_{b} \cdot b$
${h}_{b} / a = \sin \left(C\right) | \cdot a$
${h}_{b} = a \cdot \sin \left(C\right)$
$A = \frac{1}{2} a \cdot b \cdot \sin \left(C\right)$