Choose the right answer. a series of light brown lines drawn at intervals of 50 feet to designate their respective heights above sea level are called
a contour lines
b elevation lines

Contour lines

Step-by-step explanation:

A series of light brown lines drawn at intervals of 50 feet to designate their respective heights above sea level are called CONTOUR lines, or just contour.

A contour line (also called isoline) is a line that indicates points at the same elevation on the map, showing you a representation of the terrain's elevation (hills, mountains, canyons and so on).  You will find those lines on specialized maps, like topographic maps, which are different than road maps.

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.