Find factors of 12 and 21
Divide 3 from both numerator and denominator.
(12/21)/(3/3) = 4/7
4/7 is your ratio equivalent to 12/21
hope this helps
To find the unit rate of the rain per hour, we do:
3÷6= 0.5
So, the unit rate is 0.5 inch of rain/hour
Base = Height, Let them be x.

Solve quadratic equation:
x=6, x=-2(rejected because base and height is positive)
6x6/2 =18