GEOMETRY HELP Because there are 360° in a circle, multiply each percent by 360 to find the measure...
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GEOMETRY HELP Because there are 360° in a circle, multiply each percent by 360 to find the measure of each central angle. 65+ : 25% of 360 = 0.25 • 360 = 90 45–64: 40% of 260 = 0.4 • 360 = 144 25–44: 27% of 360 = 0.27 • 360 = 97.2 Under 25: 8% of 360 = 0.08 • 360 = 28.8 A researcher surveyed 2000 members of a club to find their ages. The graph shows the survey results. Find the measure of each central angle in the circle graph. Quick Check Circles and Arcs LESSON 10-6 Additional Examples
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Transcript of GEOMETRY HELP Because there are 360° in a circle, multiply each percent by 360 to find the measure...
GEOMETRYHELP
Because there are 360° in a circle, multiply each percent by 360 to find the measure of each central angle.
65+ : 25% of 360 = 0.25 • 360 = 90
45–64: 40% of 260 = 0.4 • 360 = 144
25–44: 27% of 360 = 0.27 • 360 = 97.2
Under 25: 8% of 360 = 0.08 • 360 = 28.8
A researcher surveyed 2000 members of a club to
find their ages. The graph shows the survey results. Find
the measure of each central angle in the circle graph.
Quick Check
Circles and ArcsLESSON 10-6
Additional Examples
GEOMETRYHELP
.Identify the minor arcs, major arcs, and semicircles in P with
point A as an endpoint.
Minor arcs are smaller than semicircles.
Two minor arcs in the diagram have point A
as an endpoint, AD and AE.
Major arcs are larger than semicircles.
Two major arcs in the diagram have point A
as an endpoint, ADE and AED.
Two semicircles in the diagram have
point A as an endpoint, ADB and AEB.
Circles and ArcsLESSON 10-6
Additional Examples
Quick Check
GEOMETRYHELP
mDXM = 56 + 180 Substitute.
mDXM = 236 Simplify.
mXY = mXD + mDY Arc Addition Postulate
mXY = m XCD + mDY The measure of a minor arc is the measure of its corresponding central angle.
mXY = 56 + 40 Substitute.
mXY = 96 Simplify.
Find mXY and mDXM in C. .
mDXM = mDX + mXWM Arc Addition Postulate
Circles and ArcsLESSON 10-6
Additional Examples
Quick Check
GEOMETRYHELP
C = d Formula for the circumference of a circleC = (24) Substitute.
A circular swimming pool with a 16-ft diameter will be
enclosed in a circular fence 4 ft from the pool. What length of fencing
material is needed? Round your answer to the nearest whole number.
The pool and the fence are concentric circles. The diameter of the pool is 16 ft, so the diameter of the fence is 16 + 4 + 4 = 24 ft. Use the formula for the circumference of a circle to find the length of fencing material needed.
About 75 ft of fencing material is needed.
Draw a diagram of the situation.
C 3.14(24) Use 3.14 to approximate .C 75.36 Simplify.
Circles and ArcsLESSON 10-6
Additional Examples
Quick Check
GEOMETRYHELP
length of ADB = • 2 (18) Substitute.210360
The length of ADB is 21 cm.
Find the length of ADB in M in terms of ..
length of ADB = 21
mADB 360
length of ADB = • 2 r Arc Length Formula
Because mAB = 150,
mADB = 360 – 150 = 210. Arc Addition Postulate
Circles and ArcsLESSON 10-6
Additional Examples
Quick Check
