Question

find the area of the shaded region of the concentric circle of radius 9 cm and 5 cm respectively as shown in figure 11.23​

Answer 1

Answer:

area=π (9²-5²)

       =175.93cm²

Answer 2

Hi mate! Here's Ur Answer Buddy!

Given radius of first circle be = 19 cm 1

Radius of second circle be = 9 cm 2

Let radius of required circle be Circumferenceoffirstcircle=2 =2(19)=38cm

Circumferenceofsecondcircle=2 =2(9)=18cm 2

Circumference of required circle = 2 Given that

Circumference of required circle = Circumference of first circle + Circumference of second circle

⇒ 2=38+18=56cm

⇒ = 56 = 28 2

Hence, the radius of required circle is 28 cm.

2. The radii of two circles are 8 cm and 6 cm respectively. Find the radius of the

circle having area equal to the sum of the areas of the two circles.(use = 22

Solution:

Given radius of first circle be = 8 cm 1

Radius of second circle be = 6 cm 2

Let radius of required circle be

Area of first circle = 2 = (8)2 = 64 cm2

Area of second circle = 2 = (6)2 = 36 cm2 2

Given that

Area of required circle = area of first circle + area of second circle ⇒2 =64+36

⇒ 2 = 100

Stay Awesome! #Fantods