Question 141057
he sum of the base and height of a triangle is 25 cm. What is the maximum area of the triangle? 
:
Let x = length of the base
Then
(25-x) = length of the height
:
Area = .5*L*B
Substituting of L and B
A = .5x(25-x)
A = 12.5x - .5x^2
As a quadratic equation find the axis of symmetry x = {{{(-b)/(2a)}}};
a=-.5
b= 12.5
x = {{{-12.5/(2*-.5)}}}
x = {{{12.5/1}}}
x = + 12.5 is base for max area
then
25 - 12.5 = 12.5 is the length for max area
:
A = .5 * 12.5 * 12.5
A = 78.25 sq cm is max area
: