Question 616924
As it has an angle that is 90 degrees it is a right-angle triangle and therefore cosine, sine and tangent can be used to find the angles.

As the side that is 6 long is adjacent to the known angle of 30 you can use cosine:

(Cosine (angle) = adjacent/hypotenuse

so:

Cos 30 = 6/h where h is the unknown hypotenuse.

reaarange by moving the h to the other side by multiplying both sides by h:

Cos 30 x h = 6

and then move the Cos 30 by dividing both sides by Cos 30:

h = 6/ Cos 30

now calculate using the cos function:

h = 6.93