problem solving about triangle and rectangle?!

you have 500 feet of fencing which you want to use to enclose a right triangular area. what is the largest area which you can enclose? (in square feet, enter just the number, no commas)
 
 
 
what is the area of the largest rectangle with a perimeter of 160?
 
 
 

#1  
in the case of a right triangle, the length of the sides (a, b, c) have a ratio of 1 : √3 : 2
let x = length     thus, 500 = x + √3x + 2x500 = 4.73xx = 105.66 = a      183.0 = b     211.32 = c with this information, we can calculate the area of the triangle by the formula a =1/2 base x height,= 1/2 (183 x 105.6) ≈ 9667
 
#2
the largest rectangle with a perimeter of 160 units will be a square with sides of 40 units, in which case the area will be
l x w  = 40 x 40 =1600 units