Question

If the perimeter of a semi-circular protractor is 36 cm, then its diameter is
(a)10 cm
(b)12 cm
(c)14 cm
(d)16 cm

Answer 1

Answer:

The Diameter of a semicircle protractor is 14 cm.

Among the given options option (c) 14 cm is the correct answer.

Step-by-step explanation:

Given :  

Perimeter of a semicircle protractor = 36 cm

Perimeter of a semicircle protractor ,P = circumference of a semicircle + diameter of a semicircle.

P = πr + 2r

36 = r(π + 2)

36 = r(22/7 + 2)

36 = r(22 + 14)/7

36 = r(36/7)

36 × 7/36 = r

r = 7 cm

Radius of semicircular protractor = 7 cm

Diameter of a semicircular protractor ,d = 2 × Radius semicircular protractor

d = 2 × 7  

d = 14 cm

Diameter of a semicircular protractor, d = 14 cm

Hence, the Diameter of a semicircle protractor is 14 cm.

HOPE THIS ANSWER WILL HELP YOU….

Answer 2

Perimeter of semicircle =36 cm

Perimeter of semicircle =36 cm

Perimeter of semicircle =36 cm πr+2r =36

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =36

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =3622r +14r = 252

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =3622r +14r = 25236 r = 252

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =3622r +14r = 25236 r = 252r = 252/36

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =3622r +14r = 25236 r = 252r = 252/36r = 7

Perimeter of semicircle =36 cm πr+2r =3622/7 r+ 2r =3622r +14r = 25236 r = 252r = 252/36r = 7d = 2x7=14