22:14:22 例3.输入圆半径,求圆的周长和面积 方法一:C语言的方法 #include <iostream> using namespace std void maino i float fR. fIrth. farea const float pi=3. 1415926f; cout < Enter radius: < end1 cin >>fR fIrth =2pi*fR: fArea pi*fR*fR: cout < Radius= << fR < end1; cout < Girth= < fIrth < end1 cout < Area= < fArea < end122:14:22 例3.输入圆半径，求圆的周长和面积 #include <iostream> using namespace std; void main(){ float fR,fGirth,fArea; const float pi=3.1415926f; cout << "Enter radius:" << endl; cin >> fR; fGirth = 2*pi*fR; fArea = pi*fR*fR; cout << "Radius= " << fR << endl; cout << "Girth= " << fGirth << endl; cout << "Area= " << fArea << endl; } 方法一：C语言的方法