history: what russian master spy lived in the us under the name emil goldfus?

Questions

An integer that is greater than 1 and is divisible only by itself and 1 is known as a(n) ?

Arc, radius, and sector are parts of a(n) ?

He is known as 'The Father of Geometry'?

How many corners are there in a cube?

How many nickles are there in $2.25?