Answer:
A
Step-by-step explanation:
we can find using the trigonometric formulas
we can find y by using cosine.
cos = adj / hyp
cos 60 = y / 10
y = 10 cos 60
y = 5
now we can use the Pythagorean theorem since we have the base and hyp
a² + b² = c²
5² + b² = 10²
25 + b² = 100
b² = 75
b = 5√3
