#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4);

int Menu = 0;  
float Area;
float Perimeter;
String Shape_Opt;
String Calc_Opt;
// Calculations for the Rectangle
 float lR;
 float bR;
 float Area_R = lR * bR;
 float Perimeter_R = 2*lR + 2*bR; 

// Calculations for the Triangle 
 float base;
 float height;
 float slopes;
 float Area_T = 0.5 * base * height;
 float Perimeter_T = 2 * slopes + base;

//Calculation for the Circle
 float radius;
 float pi = 3.142;
 float Area_C = pi * pow(radius,2);
 float Perimeter_C = 2 * 3.142 * radius;

// Now to setup the program.
void setup() {

  lcd.begin(20, 4);
  lcd.backlight();

  Serial.begin(115200);
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Welcome, let's Calc!");
  lcd.setCursor(0,1);
  lcd.print("Calc. in cm.");
  delay(2000);
  lcd.clear();  
  
  lcd.print("Triangle");
  lcd.setCursor(0, 1);
  lcd.print("Rectangle");
  lcd.setCursor(0, 2);
  lcd.print("Circle");
  Serial.println("Type in the Shape from the Options.\n");
  Serial.println("Triangle is an Isosceles triangle.");
}

// Now to the logic of the program.
void loop(){
  String Shape_Opt;
  if (Serial.available()){
  String Shape_Opt = Serial.readString();
  if (Shape_Opt == "Rectangle"){
    float Area = Area_R;
    float Perimeter = Perimeter_R;
    lcd.clear();
    lcd.print("Select Calc.");
    lcd.setCursor(0, 1);
    lcd.print("Area");
    lcd.setCursor(0, 2);
    lcd.print("Perimeter");

    Serial.println("Type in the Calculation to perform.\n");
    Serial.println("Calc_Opt: ");

   String Calc_Opt;
   if (Serial.available()){
   String Calc_Opt = Serial.readString();
   if (Calc_Opt == "Area"){
    lcd.print("Input Values");
    
    Serial.println("Length= ");
    float lR;
    Serial.parseFloat();

    Serial.println("Breadth= ");
    float bR;
    Serial.parseFloat();

    lcd.setCursor(0,0);
    lcd.print("Length= "); 
    lcd.print(lR);

    lcd.setCursor(0,1);
    lcd.print("Breadth= "); 
    lcd.print(bR);

    lcd.setCursor(0,3);
    lcd.print("Area= "); 
    lcd.print(Area);
    lcd.print("cm");
   }
   }
  }
  }

}