Question

The perimeter of a semicircular protractor whose radius is ‘r’ is
πr+2r
2π-2r
π+r
πr​

Answer 1

Answer:

πr + 2r

Step-by-step explanation:

Perimeter (circumference) of a complete circle is 2πr so the perimeter of a semi- circle is πr + 2r

Answer 2

Given,

Radius of semicircular protractor = r

To find,

Perimeter of the protractor.

Solution,

We can simply solve this mathematical problem by using the following mathematical process.

Now,

Perimeter of a semicircle = Half of circumference of a circle + Length of diameter

Now,

Half of circumference of the circle = 2πr/2 = πr

Length of diameter = 2 × radius = 2r

Perimeter of the protractor = πr + 2r

[This will be considered as the final answer to this question.]

Hence, the perimeter will be (πr+2r)