please help me, i only have 30 minutes!

Answer:
Radius= 13÷2
= 6.5
Step-by-step explanation:
Hope that helps
Radius = Diameter ÷ 2 = 13 ÷ 2 = 6.5 cm
Circumference = 2πr
→ Circumference = 2 × π × 6.5
→ Circumference = 13 π cm
Therefore, circumference of given circle = 13 π cm
Hope it helps you :)