You must simplify it to find the answer. You get 2 over 1 which equals just 2.
We can proceed in solving the problem since all information are given such as 2*4*5costheta.
we have a=4, b=5, and C=theta
let us solve for "c" using Pythagorean
c²=a²+b²
c²=4²+5²
c=6.4
Solving for theta or C
c²=a²+b²-2abcosC
6.4²=4²+5²-2*4*5*cosC
C=90
