Question

The first moment of area of a semi-circular area about its diameter d is given by in quora

Answer 1

Answer:

Step-by-step explanation:

Area of circle = πr^2

Area of semi circle = (πr^2) /2

Diameter d = 2 * r (radius)

=> r = d/2

Semi circular area in d is

( π * (d/2)^2 ) ÷ 2

= πd^2/ 4 * (2)

= πd^2/ 2

Answer 2

solution:

let, the area of the semi- circular area be A.

r be the radius of the semi circle.

given, the diameter of the semi circle is d.

as the diameter = 2* radius.

so, the radius,  r = d/2

since, a semi circle is the a half of a circle

so, the area of a semi circle will also be the half area of the circle.

now, A = πr^2 /2

        A = π(d/2)^2 /2

        A = πd^2 /8 unit^2