Answer:15
Step-by-step explanation:
This can be solved using a ratio. The ratio is: 13/20=x/60 this would then become 20x= 780 divide both sides by 20 and you get x=39. the answer is 39
There exists a trigonometric identity which states that,
sin (A - B) = sin A cos B - cos A sin B
This is very similar to the given expression with A equal to 57° and B equal to 13°. The simplified form of the angle is,
sin (57° - 13°) = sin 44°