Question

please say me correct answer​

Answer 1

Answer:

See below

Step-by-step explanation:

Given: It is given that there is a semicircle of radius 7 cm and we have to find the value of its area.

Now, before we proceed we should know the following two formulas:

1. For a circle of radius rr units, then the value of circumference is equal to 2πr2πr units.

2. For a circle of radius rr units, then the value of the area of the circle is equal to πr2πr2 sq. units.

Here, we will be using the formula mentioned above in the second point.

Now, let there be a circle of 7 cm. So, the value of the area of the circle can be calculated from the formula πr2πr2 where r=7r=7 cm. Then,

AreaCircle=πr2⇒AreaCircle=π×72⇒AreaCircle=49π cm2AreaCircle=πr2⇒AreaCircle=π×72⇒AreaCircle=49π cm2

Now, as we know that the semi-circle will be one half of the circle. So, the area of the semi-circle will be half of the value of the area of the circle. Then,

AreaSemi−circle=Areacircle2⇒AreaSemi-circle=49π2=492×227⇒AreaSemi-circle≈77 cm2AreaSemi−circle=Areacircle2⇒AreaSemi-circle=49π2=492×227⇒AreaSemi-circle≈77 cm2

Now, from the above result, we conclude that the area of the given semi-circle will be 77 cm277 cm2.