That is a 30 60 90 triangle.
Read about those here: http://www.1728.org/trig2.htm


This is a way to factoring trinomials (there exist different equivalent methods).
Multiply the trinomial but the term accompanying
. This is the second line. Then, you could take the square of the
, ant try to create a factor () () that will correspond to the expression in the second line. That is, we want 
In ? we put the corresponding numbers that, if we multiply them we will obtain 42, and if we add them we will obtain 13. This numbers are 6 and 7. Then, we have 
The last step is divide by the number that we multipy in the first step.
It would be 30 students from his class roster because not every kid would have his math class in the other options.
9514 1404 393
Answer:
y = 8√3
Step-by-step explanation:
In the 30°-60°-90° "special" triangle, the ratio of sides lengths is ...
1 : √3 : 2 = 8 : y : hypotenuse
In order for these ratios to be equal, we must have ...
y = 8√3
__
If you want to solve this using your trig skills, you recognize that ...
Tan = Opposite/Adjacent
tan(30°) = 8/y
y = 8/tan(30°) . . . . where tan(30°) = 1/√3
y = 8√3
WT
It does not perfectly cut the circle in half.