Use the Figure to Find the Exact Value of the Trigonometric

Multiple Choice

Use the figure to find the exact value of the trigonometric function.
Cos 2 $\theta$

a = 1, b = 2

A) $\frac { 3 } { 4 }$
B) $\frac { 3 } { 5 }$
C) $\frac { 5 } { 3 }$
D) $\frac { 4 } { 5 }$
E) $\frac { 5 } { 4 }$