#include <iostream>
#include <iomanip>
#include <cctype>
#include <string>
using namespace std;

int area(int l, int w);
double area(double b, double h);
double perimeter(double half, int b, int h);
int perimeter(int a, int bc, int c);

int main()
{
	int length, width;
	double half = .5, base, height;
	int side1, side2, side3;
	char input, input2;

	cout << "What do you want to do?\n";
	cout << "Calculate [a]rea or [p]erimeter?";
	cin >> input;

	switch (input)
	{
	case 'a':
		cout << "Calculate area of [r]ectangle or [t]riangle?";
		cin >> input2;
		
		switch (input2)
		{
			case 'r':
				{
				cout << "Enter the length and width of the rectangle: ";
				cin >> length >> width;
				cout << "Area of the rectangle: " << area(length, width) << endl;
				}
			case 't':
				{
				cout << "Enter the base and height of the triangle: ";
				cin >> base >> height;
				cout << area(base, height);
				}
		}
	case 'p':
		cout << "Calculate perimeter of [r]ectangle or [t]riangle?";
		cin >> input2;
		
		switch (input2)
		{
			case 'r':
				{
				cout << "Enter the length and width of the rectangle: ";
				cin >> length >> width;
				cout << perimeter(half, length, width);
				}
			case 't':
				{
				cout << "Enter the length of all three sides of the triangle: ";
				cin >> side1 >> side2 >> side3;
				cout << perimeter(side1, side2, side3);
				}
		}
	}
    return 0;
}

int area(int l, int w)
{
	return( l * w );
}

double area(double b, double h)
{
	return( .5 *(b * h));
}

double perimeter(double h, int l, int w)
{
	return( h * ( l+w ));
}

int perimeter(int a, int b, int c)
{
	return( a + b + c);
}