Respuesta :

wolf1728
4x + 2x = 90
x = 15

Tan (AngleA = 60) = y / 5
y = 1.7321 * 5
y = 8.6603

It seems the answer is D (though y = 8.66 and NOT 8.1)

DOUBLE-CHECK
That is a 30 60 90 triangle and 2 * shrt side = long side (AB)
so, y^2 = 10^2 -5^2
y^2 = 75
y = 8.66

So, it seems the answer is D