1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A circular park of radius 20 m is situated in a colony. Three boys Ankur, Syed and David are sitting at equal distance on its boundary each having a toy telephone in his hand to talk each other. Find the length of the string of each phone.

A

20√3

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B

40√3

No worries! We‘ve got your back. Try BYJU‘S free classes today!
C

30√3

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

10√3

No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A 20√3 Let situation of Ankur, Syed and David be A, S and D respectively in the circular path. OS = OD = OA = 20m construction: Draw OM ⊥ SA Now, AS = SD = AD (Given) So, ASD is an equilateral triangle. ∠A = 60∘ ∠MAO = 30∘ MO = AO2 [In right angled triangle, the side opposite to 30∘ is half of hypotenuse] MO = 202 = 10 AM2 = AO2 - MO2 = 202 - 102 400 - 100 = 300 AM = √300 AS = 2 AM = 2 √300 = 2 × 10√3 = 20√3

Suggest Corrections
0
Join BYJU'S Learning Program
Related Videos
Introduction - circumference
MATHEMATICS
Watch in App
Join BYJU'S Learning Program