Area of a square

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Python Practice › Basic Programs › Program 15

Area of a square

EasyBasic Programs · 15 of 40

Write a Python program to calculate the area of a square. Area = side × side.

Input
side = 6.5
Output
Area of the square: 42.25

Approach

  1. Multiply the side by itself.

Solution

Python
side = 6.5area = side * sideprint("Area of the square:", area)
Output
Area of the square: 42.25

Line by line

Line 2

side * side (or side ** 2) is the area.

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Formula (a – b)³ = a³ – 3a²b + 3ab² – b³

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Python Practice › Basic Programs › Program 14

Formula (a – b)³ = a³ – 3a²b + 3ab² – b³

MediumBasic Programs · 14 of 40

Write a Python program to solve the formula (a – b)³ = a³ – 3a²b + 3ab² – b³.

Input
a = 7, b = 2
Output
125 125 True

Approach

  1. Calculate both sides and compare them.

Solution

Python
a = 7b = 2 left = (a - b) ** 3right = a ** 3 - 3 * a ** 2 * b + 3 * a * b ** 2 - b ** 3print(left, right, left == right)
Output
125 125 True

Line by line

Line 5

3 * a 2 * b squares a first, because is evaluated before *.

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Formula (a + b)³ = a³ + 3ab(a + b) + b³

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Python Practice › Basic Programs › Program 13

Formula (a + b)³ = a³ + 3ab(a + b) + b³

MediumBasic Programs · 13 of 40

Write a Python program to solve the formula (a + b)³ = a³ + 3ab(a + b) + b³.

Input
a = 2, b = 3
Output
125 125 True

Approach

  1. Calculate both sides and compare them.

Solution

Python
a = 2b = 3 left = (a + b) ** 3right = a ** 3 + 3 * a * b * (a + b) + b ** 3print(left, right, left == right)
Output
125 125 True

Line by line

Line 5

3ab(a + b) in maths becomes 3 * a * b * (a + b) in Python; every multiplication needs an explicit *.

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Formula a² – b² = (a – b)(a + b)

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Python Practice › Basic Programs › Program 12

Formula a² – b² = (a – b)(a + b)

EasyBasic Programs · 12 of 40

Write a Python program to solve the formula a² – b² = (a – b)(a + b).

Input
a = 10, b = 6
Output
64 64 True

Approach

  1. Calculate both sides and compare them.

Solution

Python
a = 10b = 6 left = a ** 2 - b ** 2right = (a - b) * (a + b)print(left, right, left == right)
Output
64 64 True

Line by line

Lines 4-5

100 – 36 and 4 × 16 both give 64. Python does not multiply brackets automatically, so the * between them is required.

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Formula (a – b)² = a² + b² – 2ab

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Python Practice › Basic Programs › Program 11

Formula (a – b)² = a² + b² – 2ab

EasyBasic Programs · 11 of 40

Write a Python program to solve the formula (a – b)² = a² + b² – 2ab.

Input
a = 9, b = 4
Output
25 25 True

Approach

  1. Calculate both sides and compare them.

Solution

Python
a = 9b = 4 left = (a - b) ** 2right = a ** 2 + b ** 2 - 2 * a * bprint(left, right, left == right)
Output
25 25 True

Line by line

Line 4

(a - b) 2 is 5 2.

Line 5

The expanded form gives the same value, 25.

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#12EasyFormula a² – b² = (a – b)(a + b)#13MediumFormula (a + b)³ = a³ + 3ab(a + b) + b³#14MediumFormula (a – b)³ = a³ – 3a²b + 3ab² – b³#15EasyArea of a square

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Formula (a + b)² = a² + b² + 2ab

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Python Practice › Basic Programs › Program 10

Formula (a + b)² = a² + b² + 2ab

EasyBasic Programs · 10 of 40

Write a Python program to solve the formula (a + b)² = a² + b² + 2ab and show both sides are equal.

Input
a = 4, b = 5
Output
(a + b)^2 = 81
a^2 + b^2 + 2ab = 81
Equal: True

Approach

  1. Calculate the left side and the right side separately.
  2. Print both and compare them.

Solution

Python
a = 4b = 5 left = (a + b) ** 2right = a ** 2 + b ** 2 + 2 * a * bprint("(a + b)^2 =", left)print("a^2 + b^2 + 2ab =", right)print("Equal:", left == right)
Output
(a + b)^2 = 81
a^2 + b^2 + 2ab = 81
Equal: True

Line by line

Line 4

The brackets make Python add before squaring.

Line 5

binds tighter than and +, so a 2 + b * 2 + 2 * a * b follows normal maths order.

Line 8

== returns True, confirming the identity for these values.

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Pythagoras theorem

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Python Practice › Basic Programs › Program 9

Pythagoras theorem

EasyBasic Programs · 9 of 40

Write a Python program to find the hypotenuse of a right-angled triangle using the Pythagoras theorem: a² + b² = c².

Input
a = 3, b = 4
Output
Hypotenuse c = 5.0
Check: True

Approach

  1. Compute a² + b².
  2. Take the square root to get c.

Solution

Python
import math a = 3b = 4c = math.sqrt(a ** 2 + b ** 2)print("Hypotenuse c =", c)print("Check:", a ** 2 + b ** 2 == c ** 2)
Output
Hypotenuse c = 5.0
Check: True

Line by line

Line 1

math provides sqrt().

Line 5

The hypotenuse is the square root of the sum of the squares of the other two sides.

Line 7

Squaring c again confirms the theorem holds.

Tip

math.hypot(a, b) computes the same value in one call.

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Swap two variables

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Python Practice › Basic Programs › Program 8

Swap two variables

EasyBasic Programs · 8 of 40

Write a Python program to interchange (swap) the values of two variables.

Input
a = 10, b = 20
Output
a = 20
b = 10

Approach

  1. Use tuple unpacking a, b = b, a, or a temporary variable.

Solution 1: tuple unpacking

Python
a = 10b = 20 a, b = b, aprint("a =", a)print("b =", b)
Output
a = 20
b = 10

Line by line

Line 4

The right side b, a is evaluated first as the tuple (20, 10) and then unpacked into a and b, so no temporary variable is needed.

Solution 2: temporary variable

Python
a = 10b = 20 temp = aa = bb = tempprint("a =", a, "b =", b)
Output
a = 20 b = 10

Line by line

Lines 4-6

temp keeps the old value of a before it is overwritten. This is how swapping works in most other languages.

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Square and cube of a number

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Python Practice › Basic Programs › Program 7

Square and cube of a number

EasyBasic Programs · 7 of 40

Write a Python program to print the square and cube of a given number.

Input
num1 = 9
Output
Square = 81
Cube = 729

Approach

  1. Use the power operator : n 2 is the square and n ** 3 is the cube.

Solution

Python
num1 = 9 square = num1 ** 2cube = num1 ** 3print("Square =", square)print("Cube =", cube)
Output
Square = 81
Cube = 729

Line by line

Lines 3-4

** raises a number to a power. num1 * num1 and num1 * num1 * num1 give the same results.

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Median of given numbers

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Python Practice › Basic Programs › Program 6

Median of given numbers

MediumBasic Programs · 6 of 40

Write a Python program to find the median of given numbers. The median is the middle value after sorting; for an even count it is the average of the two middle values.

Input
[45, 60, 61, 66, 70, 77, 80]
Output
Median: 66

Approach

  1. Sort the numbers.
  2. If the count is odd, take the middle item at index n // 2.
  3. If it is even, average the two middle items.

Solution 1: by hand

Python
numbers = [45, 60, 61, 66, 70, 77, 80]values = sorted(numbers)n = len(values)mid = n // 2 if n % 2 == 1:    median = values[mid]else:    median = (values[mid - 1] + values[mid]) / 2 print("Median:", median)
Output
Median: 66

Line by line

Line 2

sorted() returns a new sorted list, so the original order is kept.

Line 4

For 7 values, 7 // 2 is 3, which is the index of the 4th (middle) item.

Lines 6-9

An odd count has one middle value; an even count averages the two middle values.

Solution 2: statistics module

Python
import statisticsprint(statistics.median([45, 60, 61, 66, 70, 77, 80]))print(statistics.median([3, 1, 4, 2]))
Output
66
2.5

Line by line

Lines 2-3

statistics.median() sorts and handles odd and even counts for you; for [3, 1, 4, 2] it averages 2 and 3.

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