a) The sum of the 8 identical central angles is 360°, so each one has a measure of ...
angle AOB = 360°/8 = 45°
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b) The sum of the 8 exterior angles is 360°, so each one is 45°, the same measure as the central angle. The measure of angle ABC is the supplement of the exterior angle at B, so is ...
angle ABC = 180° -45° = 135°
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In the attached image, the central point is your O. Angle AOB is the interior angle of triangle AOB whose vertex is at O.
x-2 means ur gonna take coordinate A and move it back 2 places along the x axis, (-4,-2) and then y+2 means ur gonna go up to places alomg the y axis which brings coordinate A' to (-4,0)
