Answer:
Similar triangles are (roughly speaking) triangles that have the same angles and the same ratio of the length of their sides
We can use ratios to show that the triangles are not similar
14:20 as a fraction is 14/20 as a decimal is 0.7
12:16 as a fraction is 12/16 as a decimal is 0.75
The side lengths are not the same proportion as shown by the different decimal, so the triangles are not similar