Answer:
22.2
Step-by-step explanation:
Using cosine rule,
[tex]a^{2} = 12^{2} + 15^{2} -2(12)(15)cos110[/tex]°
[tex]a = \sqrt{12^{2} +15^{2}-2(12)(15)cos110 }[/tex]
[tex]a = 22.2 (3 sf)[/tex]
