CBSE Class 8 Mathematics Question 7 of 8

The Baudhayana-Pythagoras Theorem — Question 8

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8
Question
(i) Using the dots of a grid as the vertices, can you create a square that has an area of (a) 2 sq. units, (b) 3 sq. units, (c) 4 sq. units, and (d) 5 sq. units? (ii) Suppose the grid extends indefinitely. What are the possible integer-valued areas of squares you can create in this manner?
Answer

(i) (a) 2 = 1 2 + 1 2 Mark dots A, B, C, and D as shown. Join AB, BC, CD, and DA. Then ABCD is a square and area ABCD = 2 sq. units (b) Square with area 3 units is not possible as 3 ≠ a 2 + a 2 for any integer ‘a’. (c) 4 = 2 × 2 Mark dots A, B, C, D as shown. Join AB, BC, CD, DA. Then ABCD is a square. and ar ABCD = 2 × 2 = 4 sq. units (d) (i) Mark dots A, B, C, and D as shown. Join A, B, C, and D AB 2 = 2 2 + 1 2 = 5 AB = √5 units Hence, ABCD is a square with an area of 5 sq units. (ii) Let the given value of area be x, where ‘x’ is an integer. Then, x = a 2 + b 2 , where ‘a’ and ‘b’ are integers or x is a perfect square, we can create squares with vertices as dots of the grid.