Given:

• 22 inch of pîzzà
• 18 slices of pîzza

Let radius of the pîzza = r inches

So, diameter = 2r inches

So, circumstances

• 2πr = 22
• r = 22 / 2π
• r ≈ 3.5 (approx)

So, radius = 3.5 inches

and Diameter is

• d = (2 × 3.5)
• d ≈ 7 inches

So, Area of whole pîzza

• Area = πr² in²
• Area = π (7)² in²
• Area = 49 π in²
• Area = 153.9 in²
• Area ≈ 154 in²

So, area of each part

• Area = 154 / 18 in²
• Area ≈ 8.56 in²

Therefore, the radius is 3.5 inches, the diameter is 7 inches and measure of each part is 8.56 in².