Scale Factor, Similarity, Area and Perimeter

Front

What is the scale factor in geometry?

Back

The scale factor is a number that scales, or multiplies, some quantity. It is the ratio of the lengths of corresponding sides of two similar geometric figures.

Tags

CCSS.7.G.A.1

Front

What does it mean for two shapes to be similar?

Back

Two shapes are similar if they have the same shape but not necessarily the same size. Their corresponding angles are equal, and their corresponding sides are in proportion.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

How do you find the perimeter of a shape?

Back

The perimeter is the total distance around the outside of a shape. For polygons, it is found by adding the lengths of all the sides.

Tags

CCSS.3.MD.D.8

Front

What is the formula for the area of a rectangle?

Back

Area = length × width.

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3

Front

What is the formula for the area of a triangle?

Back

Area = 1/2 × base × height.

Tags

CCSS.6.G.A.1

Front

What are corresponding sides?

Back

Corresponding sides are the sides of two or more similar figures that are in the same relative position.

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

Front

What is the relationship between the scale factor and area?

Back

The area of similar figures is proportional to the square of the scale factor.

Tags

CCSS.7.G.A.1

Front

If the scale factor is 2, what happens to the area of the shape?

Back

If the scale factor is 2, the area of the shape increases by a factor of 2² = 4.

Tags

CCSS.7.G.A.1

Front

What is the ratio of the perimeters of two similar shapes?

Back

The ratio of the perimeters of two similar shapes is equal to the scale factor.

Front

What is the scale factor if the original shape's side length is 5 and the new shape's side length is 10?

Back

The scale factor is 10/5 = 2.

Tags

CCSS.7.G.A.1