Question 14
Use this formula to check your answers in the Figure it Out on page 39.

We will use the formula for the area of a square to check the answers from the "Figure it Out" section.
Step 1 — State the formula for the area of a square
The area of a square is calculated by multiplying its side length by itself. Let represent the side length of a square.

Step 2 — Identify the shapes and their dimensions
The diagram shows two squares. Each square is divided into two right-angled triangles by a diagonal cut. Let us assume the "Figure it Out" section provides the side length for each square. Let the side length of the square containing triangles 1 and 2 be . Let the side length of the square containing triangles 3 and 4 be .

Step 3 — Apply the formula to check the answers
To check the answer for the area of the first square, we substitute its side length into the formula. Suppose the "Figure it Out" section gives an answer for the area of the first square.
We compare this calculated value with the given answer . If , then the answer is correct.
Similarly, for the second square, we use its side length . Suppose the "Figure it Out" section gives an answer for the area of the second square.
We compare this calculated value with the given answer . If , then the answer is correct.
If the "Figure it Out" section also asks for the area of individual triangles (like triangle 1), we can use the fact that each triangle is half the area of its square. So, . We would then compare this with the given answer for triangle 1.
Answer
(i) To check the answer for the area of the first square, use the formula and compare it with the given value. (ii) To check the answer for the area of the second square, use the formula and compare it with the given value. (iii) To check the answer for the area of triangle 1, calculate and compare it with the given value.
More questions in IT
How can one construct a square having double the area of a given square?
Why does the new dotted square have double the area of the original square?
In many of the constructions in the Śulba-Sūtra, it is desirable to construct, where needed, what Baudhāyana calls ‘east-west’ and ‘north-south’ lines, i.e., horizontal and vertical lines that are perpendicular to each other. Can you draw some horizontal and vertical lines to see why the new square has double the area of the original square? You could draw some horizontal and vertical lines as shown on the right.
Why should the extension of the vertical and horizontal sides of the original square pass through the vertices of the dotted square?
[Hint: From the diagonal property of a square, the line that bisects an angle passes through the opposite vertex. Argue why the vertical and horizontal sides of the original square bisect the two angles of the dotted square.**]
Context: So, the new square has double the area of the original square, because the original square is made up of two small triangles, while the new square is made up of four small triangles.
Q. Moreover, all these small triangles are congruent to each other. Can you explain why?
Now suppose we are given a square, and we want to construct a square whose area is half that of the original square. How would you do it?
Why is the smaller inside square half the area of the larger square?
Again, adding some east-west and north-south lines can explain it:
Why is PQRS a square? Why is its area half that of the original paper?
Explain by connecting QS and PR, finding the different angles formed, and then using tringle congruence.
Find the hypotenuse of this isosceles right triangle.
What is the value of ?
Is less than or greater than 1?
Is less than or greater than 2?
Can we find closer bounds for ?
Will we ever get a number with a terminating decimal representation whose square is 2?
If there is such a terminating decimal starting with 1.414... whose square is 2, then it must have a non-zero last digit. If this is the case, then the decimal representation of its square will also have a non-zero last digit after the decimal point. For example, if is of the form 1.414...4, then its square will be of the form—
Use this formula to check your answers in the Figure it Out on page 39.
What if we wish to combine two squares of 'different' sizes to make a large square whose area is the sum of the two smaller squares?
Why does Baudhāyana’s method work?
Can you see why the method works in the case where the two squares are the same size? Does it agree with the method we used earlier to combine two same sized squares into a bigger square?
Explain why all the angles of this new 4-sided figure are right angles and so it is a square.
List down all the Baudhāyana triples with numbers less than or equal to 20.
Is there an unending sequence of Baudhāyana triples?
Is (30, 40, 50) a Baudhāyana triple?
Is (300, 400, 500) a Baudhāyana triple?
Context: The list of Baudhāyana triples having numbers less than or equal to 20 contains the following triples — (3, 4, 5), (6, 8, 10), (9, 12, 15), (12, 16, 20).
Q. Do you see any pattern among them?
Context: All these triples can be obtained by multiplying each term of (3, 4, 5) by a certain positive integer.
Q. Can we form a conjecture on Baudhāyana triples based on this observation?
Context: Conjecture: (3k, 4k, 5k) is a Baudhāyana triple, where k is any positive integer.
Q. Is this true?
Is a primitive Baudhayana triple? What are the other primitive Baudhayana triples with numbers less than or equal to 20?
Generate 5 scaled versions of each of these primitive triples. Are these scaled versions primitive?
If is non-primitive, and the integers have — greater than 1 — as a common factor, then is a Baudhayana triple? Check this statement for . Justify this statement.