I saw the diagram.
1) radii: CD, CG, CF, CE, CH
2) diameter: DG, EF
3) radius: 14cm/2 = 7cm
4) diameter: 14cm because DG is the diameter, its measure is the measure of the diameter.
5) Circumference = 2 π r = 2 * 3.14 * 7cm = 43.96cm
6) Area = π r² = 3.14 * (7cm)² = 3.14 * 49cm² = 153.86 cm²