11-7 Ratio of Areas11-7 Ratio of Areas

If the scale factor of two similar figures is a:b If the scale factor of two similar figures is a:b then:then: The ratio of the perimeter (circumference) is a:bThe ratio of the perimeter (circumference) is a:b The ratio of the areas is aThe ratio of the areas is a22:b:b22..

ExampleExample

The scale factor of two circles is 5:2. The The scale factor of two circles is 5:2. The area of the small circle is 12area of the small circle is 12ππ. What is . What is the area of the big circle?the area of the big circle?

11-8 Geometric 11-8 Geometric ProbabilityProbability

ProbabilityProbability

1 – going to occur1 – going to occur 0 – not going to occur0 – not going to occur ½ - 50% change of occurring½ - 50% change of occurring

How to calculateHow to calculate

Length to be picked fromLength to be picked from

Whole lengthWhole length

Or Or

Area to be picked fromArea to be picked from

Whole areaWhole area

SPICSASPICSA

Page 470 1-23 allPage 470 1-23 all