## CS 115 Lab 7 Functions (Team)

### 80 Points

Due Date: Monday, October 23, during class

__Educational goals of this lab - verify that every student can__

- write some graphics code
- write function definitions and call them
- use the graphics objects Line, Circle, Point
- using the Text object to display text messages on the graphics window
- work with their teammates to finish a project

Use this link to submit your team result.
Use the Lab 7 menu choice and "Code" as the type.

- Use this program as a start.
- (25 points) Write a main function which accomplishes
the task: In the graphics window, it will ask
the user to click three times,
draw line segments between the 3 points
(making a triangle) and find the total length of the 3 segments
using the distance function described below.
Then display the perimeter (total length of sides).
It must call the functions described below (distance, drawLine and drawPoint).
- (15 points) Write a distance function for the program that has 2 parameters.
The parameters are points (Points in the graphics sense).
You
**must** use the getX and getY methods inside the function.
The function should calculate and return the distance
between the two points. It involves a square root.
You can use the math library function sqrt if you want.
This function does NOT output anything to the screen.
- (5 points) Write a function called "drawLine" which has 2 parameters which are Points
and one parameter which is a GraphWin.
It will create and draw a line between the two Points.
It draws it on the GraphWin.
- (15 points) Write a function called "drawPoint" which has one parameter, the graphics window. It gets a click from the user, draws a red Circle around that
point where they clicked, and returns the Point where they clicked.
- A sample run
- Another sample run
- (13 points) Now add another function called
**herons** to this program.
This function will accept the lengths of 3 sides of a triangle (the parameters)
and calculate and return the area of the triangle (return value!).
**It does not output anything to the screen.**

This is the equation for the area.
s is the sum of the 3 sides divided by 2 (called a semiperimeter).
a, b, and c are the 3 lengths of the sides of the triangle.
- (7 points) The main function should be extended to call the herons function to find
the area of the triangle input by the mouse and output that to the
graphics window.
- Sample run: