If the hypotenuse of a 30-60-90 triangle has length 15, then the shorter leg has length
5.5
6.5
7.5

its c or d   take a lucky guess my dude

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6

it would open into a square depending on the type of envelope i’m not sure about the second part

127

whether it's diameter, or radius, i believe if i remember correctly from school, every amount has to always add up to 180. so if you take 53, and starting adding, long story short, taking 127 and adding it to 53, gives you 180.