MENU
Question -

Three girls Reshma, Salma and Mandip are playing a game by standing ona circle of radius 5m drawn in a park. Reshma throws a ball to Salma, Salma toMandip, Mandip to Reshma. If the distance between Reshma and Salma and betweenSalma and Mandip is 6m each, what is the distance between Reshma and Mandip?



Answer -

Let the positions ofReshma, Salma and Mandip be represented as A, B and C respectively.

From the question, weknow that AB = BC = 6cm.

So, the radius of thecircle i.e. OA = 5cm

Now, draw aperpendicular BM AC.

Since AB = BC, ABC canbe considered as an isosceles triangle. M is mid-point of AC. BM is theperpendicular bisector of AC and thus it passes through the centre of thecircle.

Now,

let AM = y and

OM = x

So, BM will be =(5-x).

By applying Pythagoreantheorem in ΔOAM we get,

OA=OM+AM2

5=x+y— (i)

Again, by applyingPythagorean theorem in ΔAMB,

AB=BM+AM2

6=(5-x)2+y2 — (ii)

Subtracting equation(i) from equation (ii), we get

36-25 = (5-x)2 +y2 -x2-y2

Now, solving thisequation we get the value of x as

x = 7/5

Substituting the valueof x in equation (i), we get

y+(49/25)= 25

y2 =25 – (49/25)

Solving it we get thevalue of y as

y = 24/5

Thus,

AC = 2×AM

= 2×y

= 2×(24/5) m

AC = 9.6 m

So, the distancebetween Reshma and Mandip is 9.6 m.

Comment(S)

Show all Coment

Leave a Comment

Free - Previous Years Question Papers
Any questions? Ask us!
×