This diagram shows a regular dodecagon (12 sides). a) Work out the size of of one interior angle.

b) Work out the size of one exterior angle.

g

step-by-step explanation:

add an image

step-by-step explanation:

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

8+10

step-by-step explanation:

you multiply 4 by 2 and 5 by 2