PLEASE HELP !!

find the length of arc AB. round your answer to the nearest hundredth

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac