Find the area enclosed between two concentric circles, Mathematics

Assignment Help:

Find the area enclosed between two concentric circles of radii 3.5cm, 7cm. A third  concentric circle is drawn outside the 7cm circle so that the area enclosed between it and the 7cm circle is same as that between two inner circles. Find the radius of the third circle                                                                                                             (Ans: 115.5 cm 2   r = √343 / 2 )

757_circle14.png

Ans:    Area between first two circles = Π x 72 - Π x 3.52

= 49 Π - 12.25 Π -------------(1)

Area between next two circles = Π r2 - Π x 72

= Π r2 - 49 Π -----------------(2)

(1) & (2) are equal

49 Π - 12.25 Π = Π r2 - 49 Π

Π r2 = 49 Π + 49 Π - 12.25 Π

∴ r2 = 98 - 12.25 = 85.75

r2 = 8575/100 = 343/4

r =  √343/2 cm.


Related Discussions:- Find the area enclosed between two concentric circles

Solid mensuration, what is the importance of solid mensuration?

what is the importance of solid mensuration?

Algebra 1A, The m&m factory produces 2,500 packs of plain m&ms each day. R...

The m&m factory produces 2,500 packs of plain m&ms each day. Represent the total number of packs of plain m&ms the factory makes each day

Example of regression equation, Example of Regression Equation An inve...

Example of Regression Equation An investment company advertised the sale of pieces of land at different prices. The given table shows the pieces of land their costs and acreag

Why is it important the the enlightenment grew out, Why is it important the...

Why is it important the the Enlightenment grew out of the salons and other meeting places of Europe? Who was leading the charge? Why was this significant? Where there any names or

Problem of purchasing, story of faicing problem when customer purchasing a ...

story of faicing problem when customer purchasing a product

What is the difference between the two models listed above?, E1) What is th...

E1) What is the difference between the two models listed above? Which is more difficult for children to understand? E2) List some activities and word problems that you would exp

Explain how we converting fractions to percents, Explain how we Converting ...

Explain how we Converting Fractions to Percents ? To convert a fraction to a percent: 1. Convert the fraction to a decimal using long division. 2. Move the decimal point two p

Subtract, Ask question Minimum 100 words accepted# 1000-101

Ask question Minimum 100 words accepted# 1000-101

We know this equation a°=1.prove this?, we know that log1 to any base =0 ta...

we know that log1 to any base =0 take antilog threfore a 0 =1

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd