## msingh 2 years ago If an edge of a square is increased by 10%,then by how much will its surface area be increased?

1. manishsatywali

increasing a certain thing 'to' or 'by' do u understand the differnce in both of them ?????

2. manishsatywali

tell me asap

3. msingh

by

4. manishsatywali

'by' means certain fraction of total is increased or decreased here in this case it is increased

5. manishsatywali

it means here u hav to increase or add the that fraction (10/100) to the initial edge of square

6. manishsatywali

that is 10/100 = 0.1 (fraction of total )

7. manishsatywali

do u knw the formula of surface area of square?

8. msingh

6(s*s)

9. msingh

only s*s

10. manishsatywali

k gud u knw that

11. manishsatywali

now see let us suppose we hav the edge of sq. initially be 1 ..then by the defination of 'by' that i hav told u above u can add fraction (0.1) to 1 that is nw the final edge length is 1.1

12. manishsatywali

13. msingh

k

14. manishsatywali

now tell me what is the surface area of sq. with new edge length 1.1????????

15. manishsatywali

16. msingh

wait i m understanding vat u did

17. ZeHanz

Area of square with edge a is a². Edge of new square is a+10% of a = a + 0.1a = 1.1a. Area of new square is (1.1a)²=1.21a² = a² + 0.21a² = a² + 21% of a². So it is 21 % more.

18. manishsatywali

@ZeHanz PLS. DON'T GIVE DIRECT ANSWER

19. ZeHanz

@manishsatywali : Just thought you had done enough to explain. Sometimes it is better to write the whole thing down, to show the steps. If I had done this right away, I would agree with you ;)

20. msingh

(1.1a)^2

21. manishsatywali

bt i also encourage the way u deliver that in steps...........gd to see that

22. msingh

i think u both have well explained @manishsatywali and @ZeHanz

23. manishsatywali

now have you got the idea...........i mean u reach the final answer any difficulty with the method??????????

24. msingh

no of course thank u @manishsatywali and @ZeHanz

25. manishsatywali

@ZeHanz .........our combo helped @msingh......it's the best we can make out of openstudy

26. ZeHanz

@manishsatywali: thank you!