Find the square root please.

Umm.. just started this 2day and its not on my notes(p′︵‵。)

What is the number 321,000,000 in scientific notation? also what is the number? ?

Television sizes are based on the length of the diagonal of the television's rectangular screen. so, for example, a 70-inch television is a television having a diagonal screen length of 70 inches. if a 70 inch television's diagonal forms a 29°angle with the base of the screen, what is the vertical height (1) of the screen to the nearest inch? 70 inhin