Question

From a rectangular sheet of paper ABCD with AB = 40 cm and AD = 28 cm, a semi-circular portion with BC as diameter is cut off. Find the area of remining paper (use π = 22/7)​

Answer 1

Answer:

In right △AED, using Pythagoras theorem,

AD2=AE2+DE2=92+122=81+144=225cm

⇒AD=225=15cm=diameter

Required area = ar. ABCD + ar. semi-circle - ar △AED=(20×15)+21×722×(215)2−21×9×12

=300+88.3928−54=334.3928cm²

Answer 2

Step-by-step explanation:

From a rectangular sheet of paper ABCD with AB = 40 cm and AD = 28 cm, a semicircular portion with BC as diameter is cut off. Find the area -with-and-28-semicircular-portion-with-diameter-cut-offLength of rectangular sheet of paper = 40 cm Breadth of rectangular sheet of paper = 28 cm Radius of the semicircular cut out = 14 cm Area of rectangular sheet of paper = Area of rectangle = length × breadth = 40 × 28 = 1120 cm2 Area of semicircular cut out = 1/2 πr2 = 1/2 x 22/7 x 14 x 14 = 308 cm2 Now, Area of remaining sheet of paper = Area of rectangular sheet of paper – Area of semicircular cut out = 1120 – 308 = 812 Therefore, area of remaining sheet of paper is 812 cm2.Read more on