Answer:
Step-by-step explanation:
a) When 10 rays are added, there are a total of 12 rays, counting those that define the original angle. Any two will form an angle, so you're counting the number of ways that 12 rays can be chosen 2 at a time. That's ...
12C2 = 12·11/2 = 66 . . . . angles can be formed, including the original
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b) As you can tell from the above, the number of angles for n added rays is ...
(n+2)(n+1)/2 . . . . the number of ways 2 rays can be chosen from n+2 rays
Here, n is the number of rays drawn in the interior of the original angle. This number includes the original angle.
