Answer:
three
P A R
A R A D
A D I S E
P Q R
A B C D
A B C D E
<em>There are three such pairs of letters. </em>
(2÷2)+4
step by step explanation
List of the first 1000 perfect squares! ... 25, 5 * 5 . 36, 6 * 6. 49, 7 * 7. 64, 8 * 8. 81, 9 * 9. 100, 10 * 10. 121, 11 * 11. 144, 12 * ... 841, 29 * 29.