The formula to find area of circle :: **3.14 * radius * radius**

The formula to find area of triangle :: **0.5 * base * height**

Here, We are using **two classes**, one which contains** main method** and another one which contains the **sub code**.

The area class contains two method one is** circle()** that is used to find the area of circle. It takes the radius from user using** Scanner** class, and the find the area as per the formula giver above. It takes value of **PI** is defined **globally** as Constant using** final** keyword. This method is called by** object of area class** in **main()** method.

The another method is **triangle()** that is used to find the area of triangle. It takes the value of base and height from user Using **Scanner** class, and then find the area of triangle using the formula given above. It takes the value** 0.5** by using Constant variable declared in **global** by using **final** keyword. This method is called by** main()** method by using the **object of area class**.

import java.util.*; class area { float r,a,b; double aa; final double PI=3.14; final double H=0.5; Scanner sc=new Scanner(System.in); void circle() { System.out.print("\n*** AREA OF CIRCLE ***\n"); System.out.print("Enter the value of radius = "); r=sc.nextFloat(); aa=PI*r*r; System.out.print("\nArea of circle is = "+aa); } void triangle() { System.out.print("\n\n*** AREA OF TRIANGLE ***\n"); System.out.print("\nEnter the value of base = "); b=sc.nextFloat(); System.out.print("Enter the value of Altitude = "); a=sc.nextFloat(); aa=H*a*b; System.out.print("\nArea of triangle = "+aa); } } class areademo { public static void main(String args[]) { area ob1=new area(); ob1.circle(); ob1.triangle(); } }

Here is the **OutPut**

*** AREA OF CIRCLE *** Enter the value of radius = 2 Area of circle is = 12.56 *** AREA OF TRIANGLE *** Enter the value of base = 5 Enter the value of Altitude = 6 Area of triangle = 15.0