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

What is a lattice, What is a lattice? Which of the following graphs are lat...

What is a lattice? Which of the following graphs are lattice and why? Ans:  Let (L, ≤) be a poset. If each subset {x, y} consisting of any two elements of L, comprises a glb (I

Determine if following sequences are monotonic or bounded, Determine if the...

Determine if the following sequences are monotonic and/or bounded. (a)   {-n 2 } ∞ n=0 (b) {( -1) n+1 } ∞ n=1 (c) {2/n 2 } ∞ n=5 Solution {-n 2 } ∞ n=0

How many people said that red was their favorite color, In a recent survey ...

In a recent survey of 700 people, 15% said that red was their favorite color. How many people said that red was their favorite color? Find out 15% of 700 through multiplying 70

Solve the form x2 + bx - c, Solve the form x 2 + bx - c ? This tutori...

Solve the form x 2 + bx - c ? This tutorial will help you factor quadratics that look something like this: x 2 + 11x - 12 (No lead coefficient; positive middle coeffic

Euilibrium, What is partial market equilibrium

What is partial market equilibrium

Multiples, The sum of the smallest and largest multiples of 8 up to 60 is?

The sum of the smallest and largest multiples of 8 up to 60 is?

Geometry, how do you find the length of a parallel line connecting two exte...

how do you find the length of a parallel line connecting two external circles of different sizes from the outside, given the value of both radius and one parallel line.

the word rotor, a)    A palindrome is a word that reads the similar whethe...

a)    A palindrome is a word that reads the similar whether read from right to left or from the left to right, the word ROTOR, for example. Let  be the number of words of length n,

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