Answer:
B
Step-by-step explanation:
You need to find x, so you'll have to use cos in this case, because x is adjacent to the only angle you have.
So, you'll get:
cos 30 = x/10 (adjacent/hypotenuse)
Rearrange the equation for x:
x = cos 30 x 10
<em>*Since the options you have are in exact values, you can't use a calculator just to find x. </em>
Cos 30 in exact values is √3/2
<em>*you can either memorise these values or learn the trig triangles. either way, just know the exact values for sin, cos and tan for 30, 60 and 90 degrees</em>
So to find x:
x = √3/2 x 10
x = 5√3
Hope that helped : )
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