Question

Marcus wants to decorate his box that is i the shape of a cube with a color. he decides to cover the entire box with red color paper except the circular window, shown with his name on it. the box is show. rounded to nearest square centimeter, how much red paper is needed to cover Marcus box ? Marcus uses 3.14 to estimate pi

Answer 1

*see attached picture for the diagram of the box

Answer:

130cm²

Explanation

The amount of red appear needed by Marcus to cover his box = Surface Area of the cube - Area of the circle.

Surface area of cube = 6s² (where s is the side length of the cube. s² therefore is S.A of 1 face of the cube)

Given that s = 5cm,

S.A of cube = 6s² = 6*5² = 150cm²

Area of circle = πr²;

Given that π = 3.14, and r = ½ of diameter of circle (i.e. ½ of side length of cube)

Area of circle = 3.14*(½*5)² = 3.14*(2.5)² = 3.14*6.25 =19.625

Amount of red paper needed = S.A of the cube - Area of the circle = 150cm² - 19.625cm² = 130.375cm² = 130cm²