Answer: The diameter is 28cm
Step-by-step explanation:
Circumference is [tex]2\pi r[/tex] where r is the radius or just [tex]\pi d[/tex] where d is the diameter. For this, we'll use the one with the diameter.
[tex]87.92=3.14d\\\frac{87.92}{3.14} =\frac{3.14d}{3.14} \\28=d[/tex]