Respuesta :
Since we are given with the three sides of the triangle and asked to determine the angle, we can use the cosine law.
b² = a² + c² - 2ac(cosB)
Substituting the known values,
(1.8)² = (2.4)² + (1.6)² - 2(2.4)(1.6)(cosB)
The value of B from the equation is 48.6°.
Answer:
B = 60.6 degree
Step-by-step explanation:
Side AB, c = 1.2 miles
Side BC, a = 1.8 miles
Side CA, b = 1.6 miles
Use Cosine rule to find the angle B.
[tex]Cos B = \frac{a^{2}+c^{2}-b^{2}}{2ac}[/tex]
Putting the values of a, b and c
[tex]Cos B = \frac{1.8^{2}+1.2^{2}-1.6^{2}}{2\times 1.8\times 1.2}[/tex]
[tex]Cos B = \frac{3.24+1.44-2.56}{4.32}[/tex]
[tex]Cos B = 0.491[/tex]
B = 60.6 degree