If the exterior angles of a convex octagon are x +12, 2x-3, 3x +10, 3x +15, 2x - 19, 4x-1, 4x - 10, and 6x, calculate the largest of the eight angles.

Respuesta :

Answer: Largest exterior angle is 85.44 degrees

===========================================================

Explanation

Rule: The exterior angles of any polygon always add to 360 degrees

Based on that rule, we simply add up the 8 expressions given to us and set that sum equal to 360. Then we solve for x

(x+12)+(2x-3)+(3x+10)+(3x+15)+(2x-19)+(4x-1)+(4x-10)+(6x) = 360

(x+2x+3x+3x+2x+4x+4x+6x)+(12-3+10+15-19-1-10) = 360

25x+4 = 360

25x = 360-4

25x = 356

x = 356/25

x = 14.24

-------------------------------------

Once you determine the value of x, you plug that into each of the 8 exterior angle expressions

  • x+12 = 14.24+12 = 26.24
  • 2x-3 = 2(14.24)-3 = 25.48
  • 3x+10 = 3(14.24)+10 = 52.72
  • 3x+15 = 3(14.24)+15 = 57.72
  • 2x-19 =  2(14.24)-19 = 9.48
  • 4x-1 = 4(14.24)-1 = 55.96
  • 4x-10 = 4(14.24)-10 = 46.96
  • 6x = 6*(14.24) = 85.44

In short we have these 8 exterior angles

  • x+12 = 26.24
  • 2x-3 = 25.48
  • 3x+10 = 52.72
  • 3x+15 = 57.72
  • 2x-19 = 9.48
  • 4x-1 = 55.96
  • 4x-10 = 46.96
  • 6x = 85.44

We see that 85.44 degrees is the largest exterior angle (which is the angle that corresponds to the 6x). This makes sense because the 6 is the largest x coefficient compared to something like 2x-3 or 3x+10 which have x coefficients of 2 and 3 respectively.