c Note that we are looking for triangles with at least one side that is 6 cm.
A
a P=1/4
B
b P=3/4
C
c P=1/2
Practice makes perfect
a In two of the triangles, we see that some sides have hatch marks. Sides with the same number of hatch marks in the same triangle have equal lengths. With this information, we can add to the diagram.
A scalene triangle does not have any sides with equal length. Examining the diagram, we see that only one such triangle is present in the bag.
To calculate probability, we divide the number of favorable outcomes with the number of possible outcomes.
P=Number of favorable outcomes/Number of possible outcomes
Since 1 triangle of 4 is scalene, we can determine the probability of picking a scalene triangle to P= 1 4.
b An isosceles triangle has at least two sides of equal length. This means a triangle with three sides of equal length is also isosceles. Of the four triangles, we can identify three such triangles.
Since 3 triangles of 4 are isosceles, we can determine the probability of picking an isosceles triangle to P= 3 4.
c Let's identify the triangles that have at least one side that is 6 cm.
Since 2 triangles of 4 have a side measure of 6 cm, we can determine the probability of picking a triangle with at least one side that is 6 cm to P= 2 4= 12.
