SOLUTION: The sum of the base and height of a rectangle is 69 cm. Find the dimensions for which the area is maximum

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Question 848465: The sum of the base and height of a rectangle is 69 cm. Find the dimensions for which the area is maximum
Answer by ewatrrr(24785) About Me  (Show Source):
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Hi,

The sum of the base and height of a rectangle is 69 cm. 

Find the dimensions for which the area is maximum (When it is a Square)

 b + h = 69cm

 b = h = 69cm/2 = 34.5cm

the dimensions  34.5cm  by 34.5cm

Note:

 A= b(69-b)

A =  -b^2 + 69  |Completing Square to find Maximum Point

A+=+-%28b+-+%2869%2F2%29%29%5E2+%2B+%2869%2F2%29%5E2

      b = 69/2 when A is maxed and h = 69/2  (rectangle a square)