Look at the diagram. Which angle is supplementary to 1.) 2.) 3.) 4.)

it's going to be EOC

Step-by-step explanation:

I used my brain

EOC is supplementary to EOA

Step-by-step explanation:

2 supplementary angles add to 180

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

the answer is 13 cm