FOUR OF THE ANGLES OF A PENTAGON HAVE THE MEASURE 30,70, 120, AND 165. TO FIND THE MEASURE OF THE FIFTH I ADD THE FOUR MEASURES WHICH IS 385 AND SUBTRACT IT FROM 540 WHICH IS

Question

FOUR OF THE ANGLES OF A PENTAGON HAVE THE MEASURE 30,70, 120, AND 165. TO FIND THE MEASURE OF THE FIFTH I ADD THE FOUR MEASURES WHICH IS 385 AND SUBTRACT IT FROM 540 WHICH IS 
540-385=135 WOULD THIS BE CORRECT. 
IS THERE A FOMULA THAT I NEED TO USE TO ARRIVE AT MY ANSWER ? Thanks

That's almost correct. You have the right idea except 540 - 385 does not equal 135. Subtract that again and you'll get it.

You are also right that sum of the angles in a pentagon is 540. To figure that out, take the amount of sides the shape has and multiply that by 180. Then subtract 360 from that.

So the pentagon has 5 sides. 5*180 = 900. Subtract 360 and you have 540.

If it had 100 sides, the sum of all the angles would be

100*180 = 18000. 
18000-360 = 17640

Now, good luck drawing the 100 sided figure :)

Matt