I'm not for sure but I think it's ten
This is all I know. Idk if it will answer your question.
Multiply their First terms. (ac)
Multiply their Outside terms. (ad )
Multiply their Iinside terms. (bc)
Multiply their Last terms. (bd )
So, parallel lines have the same slope, therefore a parallel line to 2x+12, will have the same slope as that one, so which is it?

so, we're really looking for the equation of a line whose slope is 2, and runs through -1,1.
Answer:
Is 10cm and 6 cm an option
The one on the top should be a right triangle and the bottom one is not