Could someone explain to me how you do 13?

A3cm×3cm\greend{3\,\text{cm} \times 3\,\text{cm}} 3cm×3cm start color greend, 3, space, c, m, times, 3, space, c, m, end color greend rectangle sits inside a circle with radius of 4cm\blued{4\,\text{cm}} 4cm start color blued, 4, space, c, m, end color blued . what is the area of the shaded region? round your final answer to the nearest hundredth.

The 40th parallel of north latitude runs across the united states through philadelphia, indianapolis, and denver. at this latitude, earth’s radius is about 3030 miles. the earth rotates with an angular velocity of latex: \frac{\pi}{12} π 12 radians (or 15°) per hour toward the east. if a jet flies due west with the same angular velocity relative to the ground at the equinox, the sun as viewed from the jet will stop in the sky. how fast in miles per hour would the jet have to travel west at the 40th parallel for this to happen? show your work and explain your process.

What is the equation of the line, that passes through (3,-1) and (-1,5)