# CISC181 S2015 Lab1

From class_wiki

- Download Android Studio and install it on your machine
- Java JDK 7 is a system requirement
- JRE is a system requirement on Mac OS X. However, this worked where JRE alone didn't

- Either on your machine or on an eCalc machine in lab:
- Make a new project following these instructions
- If you haven't already, paste the following into
`MyClass`:`public static void main(String[] args) { System.out.println("Hello, world!"); }` - Confirm that you can build and run it (by pressing the green triangle button or choosing "Run" from the Run menu)

- Modify
`MyClass.java`as follows:- Add your name and section number as a
*multi-line comment* - Using a
*single-line comment*, disable the "Hello, world" print statement in`main()` - You will use
`main()`to compute several geometric identities involving a general triangle with sidelengths*a*,*b*, and*c*as shown below. Declare these variables as`double`, prompt the user to enter them, and read each in using the`Scanner`class.

- Heron's Formula gives a method to compute the area
*A*of the triangle. Follow the link and use the first formula to derive the*semi-perimeter**s*and*A*from*a*,*b*, and*c*; implement it using Java math expressions and/or functions; and report both*s*and*A*with`System.out.println()`. - The Law of Cosines can be used to calculate the angle
*γ*(gamma) between*a*and*b*(second formula in Applications section of link).`Math.acos()`will give the angle in radians; please convert it to degrees and report it with`System.out.println()` - You might notice
*a lot*of decimal places printed in your answers. Change your`println()`to`format`as necessary to only print**2**digits after the decimal for*s*,*A*, and*γ*. - Use proper naming and formatting style throughout your code.

- Heron's Formula gives a method to compute the area

- Add your name and section number as a

Submit your `MyClass.java` on Sakai by **Friday, February 13**