Question

Find the perimeter of the given diagram with the diameter 12 cm​

Answer 1

Answer:

2cm

Step-by-step explanation:

Let O be the center of the semicircle.As it being a semicircle it gives angle of $$\angle{APB}as{90}^{\circ}$$

By Pythagoras theorem in △APB

AB

2

=AP

2

+PB

2

⇒AB

2

=12

2

+16

2

=144+256=400

∴AB=20cm

And so OA=OB=10cm as r=10cm

Circumference of semicircle=πr+2r

π×10+2×10=10π+20=10(π+2)=10(3+2)=50cm

Perimeter of △=a+b+c=12+16+20=48cms

Perimeter of shaded region=50−48=2cm

Hence perimeter of shaded region=2cm