Answer:
Red circle: 30 cm
Blue circle: 60 cm
Step-by-step explanation:
The circle's circumference is calculated with
[tex]d \times \pi[/tex]
They want you to make it about how long it is so instead of pi we can just use 3 (since pi is about 3,14). The diameter (d) is double the ratio.
So now we just put in the numbers.
For the red one
[tex]10 \times 3 = 30[/tex]
The circumference is about 30 centimetres.
For the blue one
We know the ratio of the smaller so we just add together the small ratio with the rest of the length that we know so the blue one's ratio is 10 cm. (5+5=10)
And now we just put the numbers in again.
[tex]20 \times 3 = 60[/tex]
The circumference is about 60 centimetres.
