Answer:
B. 0.72
Step-by-step explanation:
In order to find the answer we need to use the following formula:
[tex]a^2=b^2+c^2-2bc*cos(\theta)[/tex] where:
a, b, c are the length of the sides and [tex]\theta[/tex] the angle, so:
[tex]7^2=10^2+8^2-(2*10*8)*cos(\theta)[/tex]
[tex]49=164-(160)*cos(\theta)[/tex]
[tex]cos(\theta)=0.71875[/tex]
In conclusion, [tex]cos(\theta)=0.72[/tex], so the answer is B.
