Answer: 39 inches
Explanation:
It's helpful to draw a triangle for these type of problems. Side j would be opposite of angle J.
The sin of an angle can be written as: sin(angle) = opposite/hypotenuse
In the triangle I drew (in the image), j is the opposite side of angle J, and the hypotenuse is 100 (which is side i, the longest one).
sin(23) = j/100
100sin(23) = j
j = 39 (make sure your calculator is in degrees mode)