I REALLY NEED HELP FAST 20 POINTS!

1. Which of the following is a proportion?

a. 9/12 = 8/10
b. 12/18 = 9/16
c. 3/4 = 9/12
d. 6/8 = 8/12

2. What is the scale factor?

Is the orthocenter of a triangle on the inside ?

Someone me what is the area of this figure? 18m 18m 8m 16m

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?