Question

(The Triangle class)

Design a class named Triangle that extends the GeometricObject class. The Triangle class contains:

- Three float data fields named side1, side2, and side3 to denote the three sides of the triangle.
- A constructor that creates a triangle with the specified side1, side2, and side3 with default values 1.0.
- The accessor methods for all three data fields.
- A method named getArea() that returns the area of this triangle.
- A method named getPerimeter() that returns the perimeter of this triangle.
- A method named __str__() that returns a string description for the triangle.

For the formula to compute the area of a triangle, see Exercise 2.14. The __str__() method is implemented as follows:

return "Triangle: side1 = " + str(side1) + " side2 = " +

str(side2) + " side3 = " + str(side3)

Draw the UML diagrams for the classes Triangle and GeometricObject.

Implement the Triangle class.

Write a test program that prompts the user to enter the three sides of the triangle, a color, and 1 or 0 to indicate whether the triangle is filled. The program should create a Triangle object with these sides and set the color and filled properties using the input. The program should display the triangle’s area, perimeter, color, and True or False to indicate whether the triangle is filled or not.

Sample Run

Enter side1: 2.5

Enter side2: 3.1

Enter side3: 2.8

Enter color: red

Enter 1/0 for filled (1: true, 0: false): 1

The area is 3.3159613990515604

The perimeter is 8.399999999999999

Color is red

Filled is True.

In Python.

Answer 1

class GeometricObject:
    def __init__(self, color="green", filled=True):
        self.__color = color
        self.__filled = filled

    def getColor(self):
        return self.__color

    def setColor(self, color):
        self.__color = color

    def isFilled(self):
        return self.__filled

    def setFilled(self, filled):
        self.__filled = filled

    def __str__(self):
        return "color: " + self.__color + " and filled: " + str(self.__filled)


class Triangle(GeometricObject):
    def __init__(self, side1=0.0, side2=0.0, side3=0.0, color='green', filled=True):
        super().__init__(color, filled)
        self.side1 = side1
        self.side2 = side2
        self.side3 = side3

    def getSide1(self):
        return self.side1

    def getSide2(self):
        return self.side2

    def getSide3(self):
        return self.side3

    def getArea(self):
        p = (self.side1 + self.side2 + self.side3) / 2
        return (p * (p - self.side1) * (p - self.side2) * (p - self.side3)) ** 0.5

    def getPerimeter(self):
        return self.side1 + self.side2 + self.side3

    def __str__(self):
        return "Triangle: side1=" + str(self.side1) + ", side2=" + str(self.side2) + ", side3=" + str(self.side3)


s1 = float(input("Enter side1: "))
s2 = float(input("Enter side2: "))
s3 = float(input("Enter side3: "))
color = input("Enter color: ")
filled = int(input("Enter 1/0 for filled (1: true, 0: false): "))
if filled == 1:
    filled = True
else:
    filled = False

t = Triangle(s1, s2, s3, color, filled)
print("The area is", t.getArea())
print("The perimeter is", t.getPerimeter())
print("Color is", t.getColor())
print("Filled is " + str(t.isFilled()) + ".")