Answer:
∠ A ≈ 48°
Step-by-step explanation:
Using the Cosine rule to find an angle
cosA = [tex]\frac{b^2+c^2-a^2}{2bc}[/tex]
with a = 10, b = 13 and c = 11
cosA = [tex]\frac{13^2+11^2-10^2}{2(13)(11)}[/tex]
= [tex]\frac{169+121-100}{286}[/tex]
= [tex]\frac{190}{286}[/tex] , thus
A = [tex]cos^{-1}[/tex] ( [tex]\frac{190}{286}[/tex] ) ≈ 48° ( to the nearest degree )
