Well, 1 Liter plus 1.5 Liters equals 2.5 Liters. We know that milli means 1000, so there are 1000 milliliters in a liters, so, all we have to do is multiply 2.5 liters by 1000 to get 2,500 milliliters!
You know one angle is 90 degrees because they are right triangles. In order to prove CES congruent to RST, you would need two legs, three angles, or a leg and an included angle.