Question 134458
The ratio of the sides of similar triangles are equal

So, the long side of the two triangle have the same ratio, the middle sides have the same ration, and the short sides have the same ration.

Thus 8/4  = 7/m = 2/s 

You are asked to find s.

{{{8/4 = 2/s}}}
{{{s = 8/8}}}
{{{s = 1}}}