Answer:
-328/34
Explanation:
Here,
Perimeter of rectangle = 6(12x+5)
Perimeter of equilateral triangle = 4(x-2)
Since they are equal, 6(12x+5) = 4(x-2)
or, 72x + 30 = 4x - 8
or, 68x = -38
or, x= -38/68 or -19/34
Now,
Area of triangle ( or rectangle whichever you prefer)
= 4* -19/34 - 8
= -76/34 - 8
= - 328/34