Geometric Probability

M217 - Geometry

Refresh…Probability - The chance that an event

will occur (a # between 0 and 1).

Geometric Probability – Probability involving geometric measures, such as length or area.

Probability and Length

P(point K is on ) = CDLength of

Length of CD

AB

A C D B

Probability and Area

P(point K is in region M) =Area of M

Area of J

J

M

Example

0 1 2 3 4 5 6 7 8 9 10 11 12

F R E M D

Find the probability that a point K, selected randomly on , is on the given segment.

1. 2.

3. 4.

FD

FR

ER

RM

DF

Example

Find the probability that a randomly chosen point in the figure lies in the

shaded region.

10

4

14

8

Example

Find the probability that a randomly chosen point in the figure lies in the

shaded region.

12

12

Time problems

If you knew there was going to be a fire drill at some point during our school day, what is the

probability that it happens before 3rd hour?

School Day: 7:30 AM – 2:45 PM

3rd hour begins @ 9:20 AM

Homework

WS 11.6A and 11.6B