## Geometry: Common Core (15th Edition)

Between the angles C and E, there are two equations containing 'a'. By setting the two equations equal to each other, you can find the value of a. $5a+12 = 9a-12$ Get the a on one side. To do this, subtract 5a from both sides, and add 12 to both sides. $24= 4a$ Divide both sides by 4 $6=a$ or $a=6$