I think the answer is 240
A = 49
You find this by adding 109 and 30, then subtracting from 180.
b = 55
c = 55
we know that the place where the two lines meet has to be 360, so we subtract the two 109s from it. Divide the answer by 2. This number is added to 54 and subtracted from 180. This gives us 55. c is in a position that equals 55.
The applicable theorem is the one that tells you the exterior angle is equal to the sum of the opposite interior angles.
9x = (5x) +(9 +x)
9x = 6x +9 . . . . . . . . collect terms
3x = 9 . . . . . . . . . . . . subtract 6x
x = 3 . . . . . . . . . . . . . divide by 3
The value of x is 3.
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The angles (clockwise from left) are then
(9*3)° = 27°
(5*3)° = 15°
(9 +3)° = 12°
This is an obtuse triangle, obviously not drawn to scale.
The answer is 300 decigrams
99.7% encompasses about 3 standard deviations either side of the mean.
82 ±3*2 = (76, 88)
About 99.7% of the values lie between 76 and 88.