Answer:

Step-by-step explanation:
From the given figure it is clear that the stop board is a regular hexagon and ∠I is an exterior angle of the regular hexagon.
Exterior angle of a regular polygon with n sides 
In a regular hexagon number of sides: n =6
Exterior angle of a regular hexagon 
Since ∠I is an exterior angle of the regular hexagon, therefore,
.
The answer is 78.5 you can get this by multiplying pi by the radius which is 5 then square it and you get 78.5
x=1
explaination:
2x+3=5x
Subtract 5x from both sides.
2x+3−5x=0
Combine 2x and −5x to get −3x.
−3x+3=0
Subtract 3 from both sides. Anything subtracted from zero gives its negation.
−3x=−3
Divide both sides by −3.
x=
−3
−3
Divide −3 by −3 to get 1.
x=1
PEMDAS use that it's gonna help you