un triángulo tiene sus lados que miden 30 cm, 23 cm, y 19 cm. selecciona el tipo de triángulo que es​

the answer is d

for problems like this theres an app, its photomath that explains the problem and gives the answer hope i

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !