What is the sum of all the common factors of 12 and 20?

What is the sum of these mixed numbers 2 1/8 + 4 3/8

Rena is building a 1: 180 scale model of a real castle. her model has a rectangular base that is 3 feet wide and 4 feet long what is the area of the base of the actual castle in square feet

(10. in the figure, a aabc is drawn tocircumscribe a circle of radius 3 cm ,such thatthe segments bd and dc are respectively oflength 6 cm and 9 cm. find the length ofsides ab and ac.