not sure if you learned S=O/H,C= A/H, T=O/A, but Sin is equal to opposite over hypotenuse, so draw a triangle, and label those angles (opposite= 3 and hypotenuse=5). Also, Cos is equal to adjacent over hypotenuse, so label those as well (you already have hypotenuse from Sin, and the Adjacent angle = 4). Therefore, Tan which equals opposite over adjacent is 3/4
