Question

यदि एक वृत्त का क्षेत्रफल 75% कम कर दिया जाये ,तो उसकी परिधि कितनी कम होगी

Answer 1

क्षेत्रफल मतलब Area
परिधि मतलब perimeter
व्यसार्द्ध मतलब radius
_____________________

Let initial area of circle = A = πR^2

If it is decreased by 75%,

New area = 100-75 = 25% of initial area

New area = 25/100 × A = 0.25A = 0.25 πR^2

Let the new radius = r

πr^2 = 0.25 πR^2

=> r^2 = 0.25R^2

=> r = √(0.25R^2) = 0.5R
____________________

Initial perimeter = 2πR

New perimeter= 2πr = 2π×0.5R = πR

decrease = 2πR - πR = πR

% decrease = πR/2πR × 100 = 1/2 × 100 = 50%

Decrease in perimeter is 50%

परिधि 50% कम हो जाएगा

Answer 2

$\orange{\boxed{\blue{\boxed{\green{Hope \: It \: May \: Help \: You}}}}}$