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Lesson Example Discussion Quiz: Class Homework

Step-5

Title: Circumference of a circle

Grade: 6-a Lesson: S2-L2

Explanation: Hello Students, time to practice and review the steps for the problem.

Lesson Steps

Step	Type	Explanation	Answer
1	Problem	The two circles are placed side by side. The first circle has a radius of 8 inches, and the second circle’s circumference is twice as long as the first circle’s circumference. Find the radius of the 2nd circle.
2	Step	Radius of a first circle (r1)	8 inches
3	Formula	Circumference of a circle	C = 2πr
4	Step	We need to determine the circumference of the first circle (C1).	C1 = \$2 \times 3.14 \times 8\$ C1= 50.24
5	Step	The circumference of the first circle (C1) is 51.48 inches.
6	Step	The circumference of the second circle is twice as long as the circumference of the first circle(C2).	\$2 \times 50.24\$ = 100.48
7	Step	We need to determine the radius of the second circle (r2) by using the circumference of a circle.	C2 = \$ 2 \times π \times r2\$ 100.48 = \$2 \times 3.14 \times r2\$ r2 = \$100.48/6.28\$
8	Step	After performing a division operation, the resulting value is	r2 = 16
9	Step	The radius (r2) of a second circle is 16 inches.
10	Answer	Option	B
11	SumUp	Can you summarize what you’ve understood in the above steps?	Audio

Step

Type

Explanation

Answer

Problem

The two circles are placed side by side. The first circle has a radius of 8 inches, and the second circle’s circumference is twice as long as the first circle’s circumference. Find the radius of the 2nd circle.

Step

Radius of a first circle (r1)

8 inches

Formula

Circumference of a circle

C = 2πr

Step

We need to determine the circumference of the first circle (C1).

C1 = \$2 \times 3.14 \times 8\$

C1= 50.24

Step

The circumference of the first circle (C1) is 51.48 inches.

Step

The circumference of the second circle is twice as long as the circumference of the first circle(C2).

\$2 \times 50.24\$ = 100.48

Step

We need to determine the radius of the second circle (r2) by using the circumference of a circle.

C2 = \$ 2 \times π \times r2\$

100.48 = \$2 \times 3.14 \times r2\$

r2 = \$100.48/6.28\$

Step

After performing a division operation, the resulting value is

r2 = 16

Step

The radius (r2) of a second circle is 16 inches.

Answer

Option

SumUp

Can you summarize what you’ve understood in the above steps?

Audio