Question

Please help on this question ​

Answer 1

21

Explanation:

If these triangles are similar, then they have the same proportions

that means that AB:BC=DM:MV

Let's fill in the unknowns

14:20=DM:30

Notice that 20 becomes 30
And that 30/20=1.5

So we multiply 20 by 1.5 to get 30...

And we multiply 14 by 1.5 to get DM

14*1.5=21

DM=21