A swimming pool is built in the shape of a rectangular prism with a length of 10.2m, a width of 7.5m and a depth of 1.5m. The floor and the sides of the pool need to be cemented.

a) Calculate the area that is to be cemented.

b) The concreter mismeasured the length of the pool as 9.4m. Calculate the error in the area of calculation.

c) Calculate the percentage error (correct to 1 decimal place) in the area calculation.

(Need to show ALL working out)

## Answers (1)

a. First work out the areas of the walls i.e. 7.5x1.5X2 + 10.2X1.5X2. Then work out the area of the floor of the pool 10.5x7.5. Add the answers to get the total area to be cemented.

b. Replace the lenght value of 10.2 with 9.4 in the calculation in part a. Find the difference between the area value you get in part a with that in part b. You have the error in area.

c. Divide your error in area in part b by the area in part a and multiply by 100. You will get the percentage error in area.

Best of luck.