If the perimeter of a triangle is 12, and the three sides a, B, C have the following relations, C = B-1, B = A-1, then the area of the triangle is______ ．

If the perimeter of a triangle is 12, and the three sides a, B, C have the following relations, C = B-1, B = A-1, then the area of the triangle is______ ．

The perimeter of the ∵ triangle is 12, ∵ a + B + C = 12, ∵ C = B-1, B = A-1, ∵ a = 5, B = 4, C = 3, ∵ 32 + 42 = 52, ∵ C2 + B2 = A2, ∵ this triangle is a right triangle, and the area of this triangle is 12 × 3 × 4 = 6

If the perimeter of a triangle is 12, and the three sides a, B, C have the following relations, C = B-1, B = A-1, then the area of the triangle is______ ．

The perimeter of the ∵ triangle is 12, ∵ a + B + C = 12, ∵ C = B-1, B = A-1, ∵ a = 5, B = 4, C = 3, ∵ 32 + 42 = 52, ∵ C2 + B2 = A2, ∵ this triangle is a right triangle, and the area of this triangle is 12 × 3 × 4 = 6

Finding the perimeter and area of triangle with C + +
#include
#include
using namespace std;
class Point{
public:
Point(double xx=0 ,double yy=0 ){
x =xx;
y=yy;
}
Point(Point&p);
double getX(){
return x ;
}
double getY(){
return y;
}
private:
double x,y;
};
Point::Point(Point&p){
x=p.x;
y=p.y;
cout

Class & nbsp; triangle {Public & nbsp;: & nbsp; & nbsp; & nbsp; & nbsp; triangle (point & nbsp; a & nbsp;, point & nbsp; B & nbsp;, point & nbsp; c); & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; double & nbsp; getpermit() {return & nbsp; len;} & nbsp; / / semicolon should

C language programming: input the radius of a hospital, calculate the perimeter and area of the hospital (the results retain two decimal places)

Entry level program
#include
#define pi 3.14
void main()
{
double r;
scanf("%lf",&r);
Printf ("perimeter:%. 2lf / N", 2 * pi * r) ";
Printf ("area:%. 2lf / N", pi * r * r) ";
}