Write down the correct number in each box:
(a) 65² = 6 x 7(100) + 5² = 4200 + 25 =_________
(b) 75² = 7 x 8(100) + 5² = 5600 + 25 =__________

3 Which of the following numbers are perfect squares? 100, 1000, 330550, 12345600000 4 Write down the correct number in the box: [For every natural number n, we have
(n + 1)² - n² = (n + 1 - n)(n + 1 + n) = (n + 1) + n.]
(a) 23² - 22² = ________
(b) 101² -100² = _________
(c) 551² - 550² = __________ 6 Which of the following triplets are Pythagorean?
(i) (1, 2, 3) (ii) (3, 4, 5) (iii) (6, 8, 10)
[We know that the three natural numbers m, n, p are said to be Pythagorean triplets if m² + n² = p².] 7 Which of the following triplets are Pythagorean?
(i) (1, 1, 1) (ii) (2, 2, 3)
[We know that the three natural numbers m, n, p are said to be Pythagorean triplets if m² + n² = p².]