Either multiply length by width, or measure all sides and add together
LxW=Area
S1+S2+S3+S4=Area
She has to 40 more laps. 50% is a half, so 40 is half of something. so you are dividing 40 by a half, which is 80. half of 80 is 40.
Answer:
A. 40
Step-by-step explanation:
A line is equal to 180 degrees. So 180-20=160. 4x=160, x=40
Answer: 
Step-by-step explanation:
The surface area of a rectangular prism can be calculated with the following formula:

Where "l" is the length of the rectangular prism, "w" is the width and "h" is the height.
In this case you can say that the length, the width and the heigth of this rectangular prism, are the following:

Knowing these values, you can substitute them into the formula shown before:

Finally, you must evaluate in order to calculate the surface area of the rectangular prism.
You get that this is:
