In the diagram below shows the cross section of a bridge with a semi circle hole. If the perimeter of the cross section is 24m. Calculate B. Area of the cross section ( π =22/7)​

the area is 85.239 m²

Step-by-step explanation:

perimeter of a semi circle = ½πd

24 = ½ x 22/7 × d

24 x 7/11 = d

15.27 m = diameter...

area = ½πr²

= ½ × 22/7 x 7.365 x 7.365

= 85.239 m2

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6