If quadrilateral abcd rotates 90° counterclockwise about the origin, what are the coordinates of a′ in quadrilateral a′b′c′d′ ?

Can any one me with the answers to these questions asap?

The ratios 3: 9, 4: 12, 5: 15, and 6: 18 are a pattern of equivalent ratios in the ratio table. which is another ratio in this pattern?

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?