What fraction is equal to 7/9 x 4/9

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)