Exterior angle theorem
16x - 7 = 8x + 2 + 10x - 19 ===> 16x -7 = 18x - 17
16x - 16x - 7 = 18x - 16x - 17 ===> -7 = 2x - 17
-7 + 17 = 2x - 17 + 17 ===> 10 = 2x ======> 5 = x
Plug x in to each equation.
Angle P: 8(5) + 2 = 42 deg, Angle Q: 10(5) - 19 = 31
The sum of interior angles = 180. 180 - 42 -31 = 107 deg (angle of PRQ)
To check that line other angle : 16(5) -7 = 73 deg + 107 = 180 deg
The answer is 2^5r^5
,.. ....
C. when opposite sides are congruent and parallel
8) The figure is a heptagon. This means the sum of the interior angles would be 180(7-2) = 5 * 180 = 900. Then this means you can say that the sum of all angles would equal 900.
(133 + 106 + 120 + 133 + (13 - 9)) + (m + m + m) = 900
-------Combine Like terms----------
496 + 3m = 900
-------Subtraction------------
3m = 404
--------Division--------
m = 404/3
If the answer doesn't seem right, just plug it in!
496 + 3(404/3) = 900
496 + 404 = 900
900 = 900
10) Same thing. The sum of the interior angles in a pentagon are 540.
(122 + 90 + 88 + 96) + k = 540
396 + k = 540
k = 144
11) The angle supplementary to the angle which measures 138 is 42. The sum of all the interior angles of a quadrilateral is 360. Let us call the missing INTERIOR angle x.
(104 + 98 + 42) + x = 360
244 + x = 360
x = 116
So the missing EXTERIOR angle is 180 - 116 which is 64.
12 is a bit confusing without showing you sorry :(
