Your sample triangle is missing, but remember that csc stands for cosecant, which is hypotenuse divided by opposite leg. Also, they tell you b=.5 and we know side b is the opposite leg to angle B since the opposite side is labeled with the same variable as the angle, just in lower case. 10 is the same number as 10/1 so now can set up a proportion of 10/1=H/.5 to solve for the hypotenuse:)