Answer:
Area of rectangle = 225/2 or 112.5
Step-by-step explanation:
Given,
Consider a rectangle ABCD.
Let AC be a diagonal of rectangle of length = 15
In triangle ABC.
Sin 45° =height/hypotenuse {SinФ = height / hypotenuse}
Here, hypotenuse = diagonal of rectangle ( i.e AC = 15)
And height is AB
Therefore, sin 45° = AB/AC
or sin 45° = AB / 15
or 1/√2 = AB /15
AB = 15/√2
Similarly we can find Base (i.e BC) using cosine.
Cos 45° = Base/Hypotenuse
Cos 45° = BC / AC
or 1/√2 = BC/15
BC = 15/√2
Hence we got length of rectangle , AB= 15/√2
And width of rectangle , BC = 15/√2
Therefore, area of rectangle = Length × Width
Area of rectangle = 15/√2 × 15/√2 = 225/2
Hence, area of rectangle = 225/2 = 112.5
The dimensions that would result to maximum area will be found as follows:
let the length be x, the width will be 32-x
thus the area will be given by:
P(x)=x(32-x)=32x-x²
At maximum area:
dP'(x)=0
from the expression:
P'(x)=32-2x=0
solving for x
32=2x
x=16 inches
thus the dimensions that will result in maximum are is length=16 inches and width=16 inches
The first choice is right, area of 1 is 20, area of 2 is 16
