Answer: 131.1287 square mm (approx)
Step-by-step explanation:
The area of a triangle,
[tex]A=\frac{1}{2} \times s_1\times s_2\times sin \theta[/tex]
Where [tex]s_1[/tex] and [tex]s_2[/tex] are adjacent sides and [tex]\theta[/tex] is the include angle of these sides,
Here PR and QR are adjacent sides and ∠R is the included angle of these sides,
Thus, we can write,
[tex]s_1 = PR= 23\text{ mm}[/tex], [tex]s_2=QR=39\text{ mm}[/tex] and [tex]\theta = 163^{\circ}[/tex],
Thus, the area of the triangle PQR,
[tex]A=\frac{1}{2} \times 23\times 39\times sin163^{\circ}[/tex]
[tex]A=\frac{262.257419136}{2} = 131.128709568\approx 131.1287\text{ square mm}[/tex]
