What is the greatest common factor of 12n and 18?

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *

Arational number that is equivalent to -20/4?