Step-by-step explanation:
solution,
circumference of circle=25.12
R=? D=2r
D=? R=x
Now,
circumference of circle =2piR
or, 22.12 = 2×22÷7 × x
or, 25.12÷2 = 22÷7 × x
or, 12.56 = 22×7x÷7
or, 12.56×7 =22×7x
or, 87.92 = 22×7x
or, 87.92 - 22 = 7x
or, 65.92 =7x
or, x = 65.92÷7
X = 9.41
R = X
R = 9.41
lastly,
D = 2r
= 2 × 9.41
= 18.83
