What is teehans?

How many 10 in 513? What shapes create a pure tessellation? What are the pairs of the factors of84? How many square ft in 0.12 acres? What is the dimension of time? Is it possible to construct a triangle with side lenghts of 6cm 11cm and 13cm? What is 20 multiplied by 12 equal? What does 62 plus 5 equal? What two whole numbers are between 138 cubed? What is the rule for 98 87 76 65? What is 15log2.5x equals 100? Why aren't sink holes found in areas where a sandstone is found at the surface? What set of numbers does 3 square root of 1 over 8? What is the perimeter of a square whose length is 25cm? Is it true that 1245 is the 13th century? What is x in 2x plus 5 equals 3? Who invented the semaphore and where? How do you solve this a tower is 1454 tall what is the height rounded to nearest hundred feet and how do you get the answer? Why do we use the rule of thirds? 4 divided by 85?