What is the area of an 100mm circle?

Answer 1

5,000 i got it right on my homework two days ago!

Formulae needed:

1. area_circle = π x radius2
2. radius = diameter ÷ 2
3. circumference = 2 x π x radius ⇒ radius = circumference ÷ (2 x π)

What do you mean by a 100 mm circle?

• Radius = 100 mm

area = π x radius2

= π x (100 mm)2

= 10000π mm2

≈ 31415.93 mm2

• Diameter = 100 mm

radius = diameter ÷ 2

= 100 mm ÷ 2

= 50 mm

area = π x radius2

= π x (50 mm)2

= 2500π mm2

≈ 7853.98 mm2

• Circumference = 100 mm

radius = circumference ÷ (2 x π)

= 100 mm ÷ (2 x π)

= 50/π mm

area = π x radius2

= π x (50/π mm)2

= 2500/π mm2

≈ 795.77 mm2