Question

Find the measure of the exterior angle. (I'm assuming it's easy I'm just bad at math.)

Answer 1

you will do area for a triangle . when multiplying with the (x+9) you will just multiply the number infront of the parentheses by both the x and the 9. for example the 60 would be 60(x+9) which would be 60x+540

Answer 2

60+x+9=2x then solve for x. x=69
plug in 69 to the exterior angle which is 2x. 2(69)=138°