Question

Please help, need fast; 30 points

What is the value of x in this figure?


A.) 103√3

B.) 5√3

C.) 5

D.) 5√2


I think its 5 or 5√3, but don't know

Answer 1

B

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

*Since the options you have are in exact values, you can't use a calculator just to find x.

Cos 30 in exact values is √3/2

*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

So to find x:

x = √3/2 x 10

x = 5√3

Hope that helped : )