Answer: AB=6.85m
∆ABC = 33.37 degree
Explanation:
Using Pythagoras theory
AB²=AC² + CB²
AB² = 3.8² + 5.7²
AB² = 14.44 + 32.49
AB² = 46.93
Take the square root of both sides.
√AB² =√46.93
AB = 6.85m
Just in case you are looking for angle B
If you want to find angle ∆ABC
To find ∆B using trig rule
Sin@ = opposite/hypotenuse
Sin@= 3.8/6.85
Sin@ = 0.55
@ = 33.37 degree