The triangles are similar.

What is the value of x?

Enter your answer in the box.

x =

PICTURE...https://static.k12.com/nextgen_media/assets/1544624-IM2_141011_020903.jpg

-Thanks :)

We could do some math here....but inspection may be faster

Notice that the corresponding sides of the larger triangle are 3 times that of the smaller triangle

So....the missing side in the larger triangle must be 3 times 7 = 21 = x