Suppose the distance from a student's eyes to the floor is 4 feet. He stares up at the top of a tree that is 20 feet away, creating a 30 degree angle of elevation. How tall is the tree?

The area of a regular nonagon (nine-sided polygon) is 900. Give its perimeter to the nearest whole number.

The area of a regular dodecagon (twelve-sided polygon) is 600. Give its perimeter to the nearest whole number.

The area of a regular pentagon is 1,000. Give its perimeter to the nearest whole number.

A nonagon is a nine-sided polygon.

Nonagon has diagonal with length 10. To the nearest tenth, give the length of one side.

In :

Evaluate to the nearest whole unit.

A decagon is a ten-sided polygon.

Decagon has diagonal with length 10. To the nearest tenth, give the length of one side.

Give the length of one side of a regular pentagon whose diagonals measure 10 each. (Nearest tenth)