Use calculator to find the squares of all natural numbers between 80 and 90.

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.] 8 Observe a pattern in the following and find the missing numbers:
22²
121 = _______
1+2+1
(333)²
12321 =_________
1+2+3+2+1
1234321 =__________
123454321 =__________
12345654321 =__________
1234567654321 =__________
123456787654321=___________
(999999999)²
12345678987654321 = ___________________________________
1+2+3+4+5+6+7+8+9+8+7+6+5+4+3+2+1 10 Guess and verify the square root of:
a) 25 b) 64 c) 81 d) 100 e) 169
f) 225 g) 400 h) 4900 i). 39 × 39 j) 320 × 320 11 Find the square root of the following by means of factors:
(a) 16 (b) 196 (c) 529 (d) 400 (e) 1764 (f) 4096
(g) 7744 (h) 11664 (i) 4900 (j) 47089 (k) 298116