357 centimeters would be your answer, this is because:
21*17=357cm
I hope this helps.
1. 24
2. 56
3. 15
4. 60
Hopefully this helps!
Area of a circle is π*r²
sub what we're given
49π= πr²
49π= π*r²
r²= 49π/π
r²=49
r=7
The diameter is twice the radius therefore the diameter is 14 units