If four angles of a convex pentagon measure 120°, 93°, 108°, and 101°, find the measure of the fifth angle.

Question

anonymous · Answer

120°+ 93°+ 108°+ 101°+x=  y

where y is the given sum of a pentagon.

anonymous · Answer

okay... so how do I work with this? (if you don't mind explaining a little...)

anonymous · Answer

well y would be  540  it is assumed you know that or are given it or you looked it up. Other wise it will be very hard if you didn't .

you then plug it in at y  

 120°+ 93°+ 108°+ 101°+x = 540   
  ^         ^          ^         ^
Add like terms  

422+x=540

now you subtract 422 from both side to isolate the x
x=118     that is your fifth angle

anonymous · Answer

they didn't give y

anonymous · Answer

oh okay. So, just add up all the other angles and subtract what's left from y?

anonymous · Answer

yup

and y is just the sum total of all the angles in the pentagon

anonymous · Answer

http://www.mathsisfun.com/geometry/interior-angles-polygons.html this will help with y :)

anonymous · Answer

Alright :3 thanks