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Warm Up Evaluate. 1. 6 4 2 2. 5.6 2 3 Simplify each expression. 3. 6 + n – 4 4. 5( n + 1) . 96. 44.8. n + 2. 5 n + 5. Problem of the Day What is the area of a right triangle with legs measuring 31 in. and 21 in.?. 325.5 in 2. Learn to find the area of a circle . - PowerPoint PPT Presentation
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10-5 Area of Circles
Warm UpEvaluate.1. 6 42
2. 5.6 23
Simplify each expression.3. 6 + n – 44. 5(n + 1)
9644.8
n + 25n + 5
10-5 Area of Circles
Problem of the DayWhat is the area of a right triangle with legs measuring 31 in. and 21 in.?325.5 in2
10-5 Area of Circles
Learn to find the area of a circle.
10-5 Area of Circles
10-5 Area of CirclesAdditional Example 1A: Estimating the Area of a
CircleEstimate the area of the circle. Use 3 to approximate .
A ≈ 3 • 202
A ≈ 1,200 m2
A = r2 Write the formula for area.Replace with 3 and r with 20.
A ≈ 3 • 400 Use the order of operations.
Multiply.
10-5 Area of CirclesAdditional Example 1B: Estimating the Area of a
CircleEstimate the area of the circle. Use 3 to approximate .
10-5 Area of CirclesCheck It Out: Example 1A
Estimate the area of the circle. Use 3 to approximate .
24.8 m
10-5 Area of CirclesCheck It Out: Example 1B
Estimate the area of the circle. Use 3 to approximate .
20 m
10-5 Area of CirclesAdditional Example 3: Application
A drum head has a radius of 18 in. Find the area of the material covering the drum head. use 3.14 for .
18 in.
10-5 Area of Circles
18 m
Check It Out: Example 3 A cymbal has a diameter of 18 in. Find its area AND circumference. Use 3 for .
10-5 Area of Circles
Standard Lesson Quiz
Lesson Quizzes
Lesson Quiz for Student Response Systems
10-5 Area of CirclesLesson Quiz: Part I
Estimate the area of each circle.
1. 2.
27 km2 1,200 yd2
10-5 Area of Circles
3. 4.
4.53 cm2 1.54 m2
Lesson Quiz: Part IIFind the area of each circle. Use for .22
7
5. A coater has a diameter of 6 inches. Find the area of the largest cup the coaster can hold. Use 3.14 for .28.26 in2
10-5 Area of Circles
1. Estimate the area of the circle. Use 3 for .
A. 48 km2 B. 46 km2
C. 44 km2
D. 42 km2
Lesson Quiz for Student Response Systems
4 km
10-5 Area of Circles
2. Estimate the area of the circle. Use 3 for .
A. 772 yd2 B. 872 yd2
C. 972 yd2
D. 992 yd2
Lesson Quiz for Student Response Systems
36 yd
10-5 Area of Circles
3. Estimate the area of the circle. Use 3 for .
A. 36.75 cm2 B. 21 cm2
C. 10.5 cm2
D. 9.19 cm2
Lesson Quiz for Student Response Systems
3.5 cm
10-5 Area of Circles
4. A circular table has a diameter of 8 feet. Identify the area of the table cloth needed to cover the table. Use 3.14 for .
A. 25.12 ft2 B. 37.68 ft2
C. 40.82 ft2
D. 50.24 ft2
Lesson Quiz for Student Response Systems
