1.50 - 0.27 = 1.23 liters
Your answer is 1.23 liters will remain.
I assume you mean one that is not rational, such as √2. In such a case, you make a reasonable estimate of it's position, and then label the point that you plot.
For example, you know that √2 is greater than 1 and less than 2, so put the point at about 1½ (actual value is about 1.4142).
For √3, you know the answer is still less than 4, but greater than √2. If both of those points are required to be plotted just make sure you put it in proper relation, otherwise about 1¾ is plenty good (actual value is about 1.7321).
If you are going to get into larger numbers, it's not a bad idea to just learn a few roots. Certainly 2, 3, and 5 (2.2361) and 10 (3.1623) shouldn't be too hard.
Then for a number like 20, which you can quickly workout is √4•√5 or 2√5, you could easily guess about 4½ (4.4721).
They're usually not really interested in your graphing skills on this sort of exercise. They just want you to demonstrate that you have a grasp of the magnitude of irrational numbers.
The answer is 67°.
Since the parallel sides of a trapezoid are called bases, the bases in our given trapezoid are AB and DC. We know that the corresponding pairs of base angles, such as ∠A and ∠D, or ∠B and ∠C, are supplementary, therefore, their angles add up to 180 degrees:
∠A + ∠D = 180°
∠B + ∠C = 180°
Given that m∠A = 113°, we can calculate for the measure of ∠D:
113° + ∠D = 180°
∠D = 180° - 113° = 67°