Question

Please solve these two. Emergently, Thank you.

Answer 1

• (D) 1/2 - 3√3/4π

Explanation:

• Problem 22 is not fully visible with missing details
• Problem 25 is solved only

Diameter = 20 cm → radius = 10 cm

Each triangle has its side equal to radius = 10 cm

Each shaded region is the difference of area of the sector and triangle

Each sector is 60° as triangles are equilateral

Area of circle is:

• πr² = 100π

Area of each triangle is:

• √3/4a² = √3/4r²= 100×√3/4

So the shaded area is:

• 3(πr²/6 - √3/4a²) =
• 3(π×10²/6 - √3/4×10²) =
• 100(π/2 - 3√3/4) =
• 100π(1/2 - 3√3/4π)

Since 100π is the area of circle, the shaded area is:

• 1/2 - 3√3/4π part of area of circle if we divide the shaded area by the area of circle.

Correct choice is D