11.2    Linear Measure

**KEY**        Bigger to Smaller “X”

Smaller to Bigger “/”

English System

1 yd = 3 ft

1 ft = 12 in

1 mi = 1760 yd or 5280 ft

Ex. Convert 5.25 mi to yds

Ex. If a cheetah is clocked at 60mph, what is its speed in ft/sec?

Convert each of the following:

1. 219 ft = __________________________yd

1. 8432 yd = ________________________mi

1. 0.2 mi = _________________________ft
2. 64 in = __________________________yd

The Metric System

1 km = 1000 m ----kilometer

1 hm = 100 m ----hectometer

1 dam = 10 m ----dekameter

1 m = base unit ----meter

1 dm = 0.1 m ----decimeter

1 cm = 0.01 m ----centimeter

1 mm = 0.001 m ----millimeter

Convert each of the following:

1. 1.4 km = __________________________m

1. 285 mm = _________________________m

1. 0.03 km = _________________________cm

1. 262 m = __________________________km

Distance Properties

Notice the triangle inequality

Def. Perimeter of simple closed curves—the length of the curve (polygon) is the sum of the lengths of all its sides (that is, it has linear measure).

Ex. Find the perimeter of each polygon:

Circumference of a Circle

Def. Circle—the set of all points the same distance from  the center, c, of the circle.

Perimeter = Circumference = 2πr

Find each of the following:

1. The circumference of a circle with r = 2m

1. The radius of a circle with C = 15πm