Answer:
C.
Step-by-step explanation:
x is bisecting the baseline (cutting it in 2 halves of 6).
the third angle in the main overall triangle is 60 degrees.
remember, all angles in a triangle always add up to 180 degrees.
so, 180 - 60 - 60 = 60.
that means that all 3 angles are of equal size (60). and that means that all 3 sides must have the same length.
=> y = 12
and now using Pythagoras to calculate the height (x) of the triangle :
y² = x² + 6² (remember, this side is only half the baseline)
12² = x² + 6²
144 = x² + 36
x² = 108
x = sqrt(108) = sqrt(36×3) = 6×sqrt(3)
