Answer:
∠T=22°
Step-by-step explanation:
Given triangle RST with sides 5 cm, 7 cm, 3 cm.
If all sides are given and find the missing angle, we use cosine rule
[tex]CosA=\frac{b^{2}+c^{2} -a^{2}}{2bc}[/tex]
Where,
sides are a, b, c and angle A, B, & C are opposite angles respectively.
So,
[tex]CosT=\frac{r^{2}+s^{2} -t^{2}}{2rs}[/tex]
[tex]cosT=\frac{25+49-9}{70}[/tex]
[tex]cosT=\frac{65}{70} =\frac{13}{14}[/tex]
T = 21.79°≈ 22°
That's the final answer.
