FIND PERIMETER, CIRCUMFERENCE

WARM-UP

• In the figure above, APB forms a straight line. If the measure of angle APC is eighty-one degrees larger than the measure of angle DPB, and the measures of angles CPD and DPB are equal, then what is the measure, in degrees, of angle CPB?

A. 33 B.40 C. 66 D. 50 E. 114

DEFINITIONS

• Perimeter – the distance around a figure

• Circumference – the distance around a circle

Measured in units of length Ex. Meters (m) or Feet (ft)

FORMULAS FOR PERIMETER (P), AREA (A), AND CIRCUMFERENCE (C)

EXAMPLES..

P = 2(14) + 2(9)

P = 46 ft

P = 13 + 12 + 5

P = 30 in

C = 2(3.14)(15)

C = 94.2 yd

EXAMPLE 1

What is the perimeter of the rectangular basketball court shown?

2 84 + 2(50)

168 + 100

268 𝑓𝑡

EXAMPLE 2

• Triangle QRS has vertices Q(1, 2), R(4, 6), and S(4, 2). What is the approximate perimeter of triangle QRS?

QR: (4 − 1)2+(6 − 2)2 QR: 5

QS: (4 − 1)2+(2 − 2)2 QS: 3

RS: (4 − 4)2+(2 − 6)2 RS: 4

𝑃 = 3 + 4 + 5

Q

R

S

CLOSURE

• Find the circumference.