Answer:
D
Step-by-step explanation:
The circumference (C) of a circle is calculated as
• C = πd ( d is the diameter )
From the diagram
the diameter (d) is the hypotenuse of the given right triangle
Using Pythagoras' identity in the right triangle
• c² = a² + b² ( c is the hypotenuse and a, b the legs )
let a = 20, b = 21 and c = d ( the diameter ) , then
d² = 20² + 21² = 400 + 441 = 841 ( take square root of both sides )
[tex]\sqrt{d^2}[/tex] = [tex]\sqrt{841}[/tex]
d = 29
Then
C = πd = 29π
