sides. Looking at the diagram to the left, which of the following is a possible
length of side x?
A) 19
B) 20
C) 21
D) 22
The sum of the other two sides is 20, their difference is 6, so 6 < x < 20. The
only answer choice that works, then, is A.
But most triangle questions will deal with one of two concepts: similar
triangles and right triangles.
Similar triangles: Though there have been no new developments in similar
triangles for more than 2,000 years, they’re still in fashion with the SAT. So don
your toga and get psyched for the bacchanalian triangle party!
Don’t ever change, similar triangles. We love you just the way you are.
—Samantha
What are similar triangles? Similar triangles are two or more triangles with
congruent angles and proportional sides. Here, for example, are two similar