Answer-
The area of QRS is 238.7 sq units.
Solution-
According to properties of supplementary angles,
[tex]m\angle R+124=180\\\\m\angle Q+132=180[/tex]
So,
[tex]\Rightarrow m\angle R=180-124=56,\ m\angle Q=180-132=48[/tex]
As the sum of measurement of all the angles in a triangle is 180, so
[tex]\Rightarrow m\angle S+m\angle R+m\angle Q=180[/tex]
[tex]\Rightarrow m\angle S=180-m\angle R-m\angle Q[/tex]
[tex]\Rightarrow m\angle S=180-56-48=76[/tex]
Then the area of the triangle will be,
[tex]\text{Area}=\dfrac{1}{2}qr\sin S[/tex]
[tex]=\dfrac{1}{2}\times 21\times 23.43\times \sin 76[/tex]
[tex]=238.7\text{sq.units}[/tex]