I'll use the list of referents you had on your other question and I believe this is a reference to that list.
Part A:
Use the reference of an adult stride (about 1 yard) to estimate the dimensions and length of the lawn edging. The dimensions can be used to find the area, in square yards, that is required to fill both sides of the flower beds.
Part B:
Similarly, you can use an adult stride of about 1 yard as a reference to measure to dimensions of the paved area and the dimensions of the brick. Using these dimensions, you can find area of the paved walkway and the area (surface area of top only) in square yards. Use these areas to find the approximate number of bricks needed to fill the walkway.
