im not sure If Im correct but heres my thoughts:
since it is a equalateral rectangle, the all the sides are equal to its corresponding side, meaning the length= the other length and the width= the other width of the rectangle.
Now knowing this,you can split the triangle and rectangle by drawing a line between and the line value is 24, since mentioned above, length=length.
We have figured out all the sides of the rectangle and now only need to find the other small side of the triangle.
Using pythagroean theorum, a^2+b^2=c^2, you can set the unknown part of the triangle to a^2.
plugging in the values: a^2+24^2=25^2, you can further simplify and get a as 7
Now that we have all the values, you can just add all the sides EXCLUDING the 24 of the imaginary length in the rectangle since we only needed that to find the other side of the triangle.coming to 13+24+13+7+25= 82, which is the perimeter
hope this helped,
Im rusty in geo so im giving my best shot
An equalateral triangle means everything by sides and degrees are equal in each other.
The given degrees is (3x-33). Knowing its an equaliteral triangle that add up to 180 in degrees, you can add them up and set them to 180.
it will look something like this : (3x-33)+(3x-33)+(3x-33)=180
plugging that in, you know for sure that its correct since all three angles add up to 180.
This x value will be what we need to solve the sides and furthermore AT.
You already know x and that the sides equal to each other so you can just plug in to the given of 9x+69.
which gives line AT=348
hope this helped, and if im wrong, someone please back me up