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The base of the triangle is increased by 40%. What can be the maximum percentage increase in the length of the height so that the increase…

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The base of the triangle is increased by 40%. What can be the maximum percentage increase in the length of the height so that the increase in area is restricted to a maximum of 60% ?
  • A14.95%  
  • B14.98%
  • C14.28%
  • D14.45%
Answer not set
0
CCommunity
14.28%
0
CCommunity
Consider the provided information.

Let the height of the triangle is h and base is b.

It is given that height increased by 40%

New height = h + 40% of h

New height =
[Image: https://tex.z-dn.net/?f=h%2B%5Cfrac%7B2%7D%7B5%7Dh%3D%5Cfrac%7B7%7D%7B5%7Dh]


The area of triangle is:
[Image: https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D(b%5Ctimes%20h)]


Let new base be x, then

Thus,
[Image: https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D(x%5Ctimes%20%5Cfrac%7B7%7D%7B5%7Dh)]


The Area increases by 60%. so, new area,


[Image: https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D(b%5Ctimes%20h)%2B%5Cfrac%7B60%7D%7B100%7D%5Ctimes%5Cfrac%7B1%7D%7B2%7D(b%5Ctimes%20%5Cfrac%7B7%7D%7B5%7Dh)]



[Image: https://tex.z-dn.net/?f=A%3D%5Cfrac%7B8%7D%7B5%7D%5Ctimes%5Cfrac%7B1%7D%7B2%7D(b%5Ctimes%20h)]


Substitute the value of A from above.


[Image: https://tex.z-dn.net/?f=%5Cfrac%7B8%7D%7B5%7D%5Ctimes%5Cfrac%7B1%7D%7B2%7D(b%5Ctimes%20h)%3D%5Cfrac%7B1%7D%7B2%7D(x%5Ctimes%20%5Cfrac%7B7%7D%7B5%7Dh)]



[Image: https://tex.z-dn.net/?f=%5Cfrac%7B8%7D%7B5%7D%5Ctimes%20b%3D%5Cfrac%7B7%7D%7B5%7Dx%5C%5C%5C%5Cx%3D%5Cfrac%7B8%7D%7B7%7Db]


So, base will increase by 1/7th of b=14.28%.