Question

A circular mirror of radius 21 cm is surrounded by a circular frame of
width 3.5 cm. Find the cost of making the frame at 15 per cm square
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Answer 1

Answer:

Here is your answer and you should report all his questions as well ( the one who answered something very inappropriate )

Step-by-step explanation:

Let radius of mirror = 21 cm

circular frame of width is 3.5 cm

Therefore radius of mirror + frame = 21 cm + 3.5 cm = 24.5 Cm

Now area of the frame = ( R raise to 2 - R raise to 2 ) Here R = 24.5 cm , r = 21 cm and pie = 3.14

A = pie ( R^2 - r ^2 ) = Pie ( R-r ) ( R +r ) cm^2

A = pie ( 24.5^2 - 21^2 ) = 22/7 ( 24.5-21)

(24.5+21) cm^2

A = pie ( 24.5^2 - 21^2)

A = 22*0.5*45.5 = 500.5 cm ^ 2

Cost of making frame for 1 cm is 1.50

TOTAL COST OF 500.5 CM ^ 2 *1.50

= 750.75

THEREFORE RUPEES NEEDED FOR FRAMING THE MIRROR = Rs 750.75