Respuesta :

Answer:

Step-by-step explanation:

let one diagonal=x

other diagonal=3x

area=1/2 (x±3x)=3/2 x²=54

x²=54×3/2=81

x=9 cm  

3x=3×9=27

sum of diagonals=x+3x=4x=4×9=36 cm

RELAXING NOICE
Relax