What is the name of the branch of Probability that deals with the experiments with Uncountably Infinite outcomes? I am having lectures that is repeatedly discussing the experiments like the following:

We draw two points $p$ and $q$ at random from the interval $[-1, 1]$. Let $x_1$ and $x_2$ denote the roots of the equation $x^2 + px + q = 0$.
Find the probability that:
(a) $x_1, x_2 \in \Bbb R$
(b) ${x_1}^2 + {x_2}^2 &lt; 1$

My instructor says that, this is called Continuous Probability. But, I am not finding any chapter or topic of the name Continuous Probability in any books of introductory probability.
There are some topics named Continuous Random Variable, or, Continuous Probability Distribution. But, they seems to be not dealing with these types of problems. Am I missing something?
Where can I find materials to study and solve these Continuous Probability problems?
I am in trouble. Please, help me.
It's called a geometric probability, most of the introductory books cover this topic as an example but they don't dedicate much effort to it. If you want a dedicated book, you may look at (for example): Klain, Rota, Introduction to Geometric Probability, CUP (available online).
It's called a geometric probability, most of the introductory books cover this topic as an example but they don't dedicate much effort to it. If you want a dedicated book, you may look at (for example): Klain, Rota, Introduction to Geometric Probability, CUP (available online).