Please help me!
The center of each circle in the figure lies on the number line. Complete the description of the relationship between the circumference of the largest circle and the circumferences of the four smaller circles.

The circumference of the largest circle is (drop list options: double, equal to, 10 times, half) the sum of the circumferences of the four smaller circles.

The circumference of the largest circle is _ π.

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?