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 2θ​ ​
A = 1,b = 2
​

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