Basic probability
What is probability?
The likelihood that an event will happen
What is geometric probability based on?
Area or length
How many degrees are in a circle?
360
How many sides does a triangle have?
3
What is the distance across a circle called?
Diameter
If you flip a coin, what is the probability of heads?
1/2
If a point is randomly placed on a line segment, what determines probability?
Length of the segment
what is the probability of landing on a 90 degree section of a spinner?
1/4
What is the sum of angles in a triangle?
180 degrees
What is half of the diameter called?
Radius
If a dice has 6 sides what is the probability of rolling a 3?
1/6
A point is inside a square. Probability it lands in a smaller square depends on what?
Area ratio
A spinner has 8 equal sections, what is the probability of one?
1/8
Probability of picking an equilateral triangle from 3 types (equal chance)?
1/3
What is circle area formula
pi r2
What is the probability of rolling an even number on a dice?
1/2 or 3 out of 6
If a dart hits a circular board, what determines probability of hitting a region?
Area of the region divided by total area
whats the probability of a 120 degree section on a spinner
1/3
If 2 out of 5 triangles are right triangles, probability of choosing one?
2/5
if a point is randomly chosen inside a circle. What is the probability it lands closer to center than the edge?
1/4
small area /big area
small- 1/4 pi r2
big- pi r2
What is the probability of drawing an red card from a standard deck?
26/52 or 1/2
A square has area 16. A smaller square inside has are 4. Probability of landing in smaller square
1/4
A spinner has 3 sections, each section is 60, 120 and 180 degrees. What is the probability of each
Ex: 120 degrees
1/3 ( 120/360)
A triangle is chosen at random: 4 scalene, 3 isosceles, 3 right. Probability of isosceles?
3/10
a circle has a radius of 2. A smaller circle inscribed has a radius of 1. whats the probability of landing in the smaller circle
(pi * 12) / ( pi * 22)= 1/4