Probability that involves a geometric measure such as length or area is called geometric probability. Suppose that a region A contains a region B.
Suppose now that a point Q in region A is chosen at random. Then, the probability that point Q is in region B is given by the ratio of the area of region B to the area of region A.
P(Qis inB)=Area of regionB/Area of regionA
We can also use angle measures to find geometric probability. The ratio of the area of a circle sector to the area of the entire circle is the same as the ratio of the sector’s central angle to 360. With this in mind, let's consider the given diagram.
We want to find the probability of the pointer landing on red. We can see that the angle measure of the red region is 92^(∘). Knowing that the full circle has a central angle whose measure is 360, we can write the ratio to find the desired probability.
