Answer:
x=28
Step-by-step explanation:
Hi there!
SSS similarity theorem is a theorem that can determine similar triangles; the criteria for SSS~ is that the corresponding sides of the triangles create proportions which is the same as the ratio of similitude (k)
First, we need to find the ratio of similitude.
We need to assume that the triangles are similar.
15 corresponds with 20 (if you turn both triangles until they're titled the same way, you will see that 15 and 20 are the measures of the same sides on the triangles)
so that means 15/20 must make the ratio of similitude
15/20 is equal to 3/4
therefore k=3/4
as the triangle is already assumed similar, that means that 21/x will also give us a ratio that is equal to 3/4 (ratio of similitude)
therefore, 21/x=k
Since both ratios are equal to k, set 3/4 and 21/x equal to each other. This is possible via a property called transitivity (if a=b and b=c, then a=c)
3/4=21/x
cross multiply
3x=84
divide both sides by 3
x=28
So that means that 28 will make the triangles similar by SSS similarity
*you double check by doing 21/28 and see that it's also equal to 3/4
Hope this helps!
