The choices are...
A. 8
B. 10
C. 15
D. 6
E. 9
F. 12

Since the triangle and the square have the same perimeter:

perimeter of triangle = perimeter of square

Finding the perimeters of the shapes:

Perimeter of triangle:

5x + 5x + (x-3)                            [sum of all sides]

10x + x - 3

= 11x - 3

Perimeter of square:

Perimeter of square = 4 * side

Perimeter of square = 4 * (x + 15)

Perimeter = 4x + 60

Finding 'x':

since perimeter of triangle = perimeter of square

11x - 3 = 4x + 60

11x - 4x = 63

7x = 63

x = 9

here you hope this .

step-by-step explanation:

hypotenuse = √(15² + 8²)

=  √(225 +64)

=  √(289) = 17

sin(x) = cos(y) = 8/17

they are identical so long as you are doing the sine of one angle and the cosine of the only other angle that isn't the right angle.

the answer is (4,3)

since the rule for r0, 90º is (-y,x) and it was already applied to form the image, all you have to do is reverse the answer using this formula.