(prove) if two lines intersect , vertically opposite angle are equal

So me with this math problem. find the value of x the table shows the masses of 50 eggs. mass: 40-44 eggs: 6 mass: 45-49 eggs: x mass: 50-54 eggs: 12 mass: 55-59 eggs: 10 mass: 60-64 eggs: 7 mass: 65-69 eggs: 2 you!

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Ineed with math stuff it involves graphs