NEED MATH HELP?

Here's the problem:
A landscaper is to install edging around a garden. The edging costs $1.39 for each 24-inch-long strip. The landscaper estimates it will take 4 hours to install the edging
a: If the total cost is $120.30, what is the cost of the material purchased?
b: What is the charge for labor?
Also there is a picture of a semicirclewith a diameter of 8ft and with 2 triangles sticking out with a base of 4ft and a height of 3ft at the side next to the problem.
Thanks and please show your work! ^^