Answer:
B
Step-by-step explanation:
Given a triangle with two angles and a side, then to find a side.
Use the Law of Sines
• [tex]\frac{sinA}{a}[/tex] = [tex]\frac{sinB}{b}[/tex] = [tex]\frac{sinC}{c}[/tex]
where a, b , c are the sides opposite ∠ A, ∠ B and ∠ C respectively.
given ∠ A = 45° , ∠ B = 40° and a = BC = 7 , then find b using the first two ratios of the Law of Sines, that is
[tex]\frac{sinA}{a}[/tex] = [tex]\frac{sinB}{b}[/tex] , then
[tex]\frac{sin45}{7}[/tex] = [tex]\frac{sin40}{b}[/tex] ← equation to solve for b
