Contact us
Choose a category below so we can get back to you as quickly as possible.
內半徑28.26÷3.14÷2=4.5米 外半徑4.5+1=5.5米 面積3.14×(5.5×5.5-4.5×4.5)=3.14×10=31.4平方米
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.