Answer:
66
Step-by-step explanation:
subtract each external angle by 180 to find the interior angle.
Since you know that all of the interior angles add up to 540 because 180(n-2)
with n is how many sides in the polygon
so 180(5-2)=540
now take each value and subtract it by 180
180-(45)=135
180-(40)=140
180-(x)=180-x
180-(77)=103
180-(2x)=180-2x
135+140+180-x+103+180-2x=540
738-3x=540
x=66
hope that helps :)
Please give brainliest
