Answer:
Step-by-step explanation:
Law of sines says that the length of sides are proportional to the sine of the opposing angle.
Using the sine rule,
sin(x)/2.5 = sin(28)/3
therefore
sin(x) = 2.5 * sin(28) / 3
or
here we have
x = asin (2.5*sin(28) / 3)
so
box 1 = 2.5
box 2 = 28°
box 3 = 3
