Answer:
The answer is option B
2.1
Explanation:
To find the length of a we use the cosine rule
That's
a² = b² + c² - 2bc cos A
We have
a² = AB ² + AC ² - 2(AB)(AC) cos A
From the question
AB = 6
AC = 5
A = 20°
Substituting the values into the above formula we have
a² = 6² + 5² - 2(6)(5) cos 20
a² = 36 + 25 - 60cos 20
a² = 61 - 56.38
a² = 4.62
Find square root of both sides
a = √4.62
We have the final answer as
a = 2.1
Hope this helps you