Answer:
7. r = d/ 2, d = 26.5
r = 26.5/2
r = 13.25mm
8. C = πd, d = 26.5
C = 26.5π
C = 83.2522053201
≈ 83.25mm (nearest hundredth)
≈ 83.3mm (estimated)
9. A = πr², r = 13.25
A = (13.25)²π
A = 175.5625π
A = 551.545860246
≈ 551.55mm (nearest hundredth)
≈ 552mm (estimated)
Hope this helps. ^^