Question

a paper is in the form of a rectangle pqrs in which PQ is equal to 10 cm and QR is equal to 7 cm to semicircular portions with QR and PS as diameters are cut off. find the area of the remaining part

Answer 1

Given, Length (PQ)= 10cm

Given, Breadth (QR) = 7cm 

Area of Rectangle PQRS will be = 10 * 7
                                         
                                                     = 70cm^2

Given that two semicircles of Diameter QR and PS are cut off, then

Area of remaining part will be Area of the rectangle - Area of the semicircle

Area of semicircle =  pi * r * r/2

                               = (22/7 * 3.5 *3.5 )/2
 
                               = 38.5/2

                              = 19.25cm^2


Area of two semicircles = 19.25 + 19.25
  
                                        = 38.50cm^2

Area of remaining portion = 70 - 38.50
 
                                            = 31.50cm^2.


Hope this helps!

Answer 2

Answer:

given , length (pq) = 10 CM

Given , breadth (qr) = 7 CM

Area of rectangle pqrs will be = 10×7 =70 cm^2

Given that two semicircles of diameter qr and PS are cut off then

Area of remaining part will be Area of the rectangle - Area of the semicircles

Area of semi circle = pi×r×r/2

22/7×3.5×3.5/2

38.5/2

=19.25 cm^2

Area of two semicircles = 19.25+19.25=38.50 cm^2

area of remaining portion = 70-38.50 = 31.50cm^2