Answer:
Cr = 10
Step-by-step explanation:
To calculate combinations we use the nCr formula: nCr = n! / r! * (n - r)!, where n = number of items, and r = number of items being chosen at a time.
![C(n,r)=[?]](https://tex.z-dn.net/?f=C%28n%2Cr%29%3D%5B%3F%5D)




[RevyBreeze]
140 degrees because an angle of a circle is 360 degrees and you can subtract these angles from it to get 140 degrees
Use the pythagorean theorem. You should come out with C. Hope this helps!