What is the relationship between the decimals 0.09 and 0.9

Solve the right triangle abc with right angle c, if b=30 degrees, and c = 10 a.) a=5, b=5, a=60 degrees b.) a=5, b=8.6602, a=60 degrees c.) a=5.7735, b=11.5470, a=60 degrees d.) a=8.6602, b=5, a=60 degrees