Work out tan(19pi/4) without a calculator

Asquare is dilated by a scale factor of 1.25 to create a new square. how does the area of the new square compare with the area of the original square? a)the area of the new square is 1.25 times the area of the original square. b)the area of the new square is 2.50 times the area of the original square. c)the area of the new square is 1.252 times the area of the original square. d)the area of the new square is 1.253 times the area of the original square.

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.