Two semicircles are used to make the shaded shape below. One semicircle has a diameter of 16 cm and the other has a diameter of 20 cm.
-20 cm
-16 cm
Diagram not drawn to scale
Work out the perimeter of the shaded shape.

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

The appalachian trail is a hiking trail that passes through the appalachian mountains. three members of a teen hiking group hiked a section of the trail. the hikers stopped at a rest area and equally shared 3 4 gallon of water. how much water did each person get?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed