Question

Martha found a rectangular box wrapped in beautiful Christmas wrapping under

the Christmas Tree. The present was 20 cm high and twice as long as it was wide.
If it had a surface area of 1600 cm?, what was the volume of the present?

Answer 1

To find the volume, we first need to determine the dimensions of the rectangular box. Using the given information about the height and length, we can set up an equation to find the width. Solving the equation will give us the dimensions needed to calculate the volume.

Step-by-step explanation:

To find the volume of the present, we first need to determine the dimensions of the rectangular box. We know that the height is 20 cm and that the length is twice the width.

We can represent the width as x, so the length would be 2x. The surface area of the box can be calculated using the formula SA = 2lw + 2lh + 2wh. Plugging in the values, we have 1600 cm² = 2(2x)(x) + 2(20)(2x) + 2(20)(x).

Simplifying the equation, we get 1600 cm² = 4x² + 80x + 40x.

Next, we need to solve this quadratic equation to find the values of x. Once we have the width, length, and height, we can calculate the volume using the formula V = lwh.

Answer 2

32,000cm²

Step-by-step explanation:

It already has an area which is lengh×width

So you only have to multiply with the height which is 20.