The law of cosines is a2+b2 - 2abcosc = c^2 find the value of 2abcosc a. 40 b. -40 c. 37 d. 20

(the sides are 2,4, and 5; a to b is 2, b to c is 4, and a to c is 5.)

Atoy company is considering a cube or sphere-shaped container for packaging a new product. the height of the cube would equal the diameter of the sphere . compare the volume to surface area ratios of the containers. which packaging will be more efficient? for a sphere, sa =4πr²

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.

Ineed the solution to this problem and the steps.