"quadrilateral ABCD is similar to quadrilateral QRST"(rs)/(bc) (?)/(dc)

Question

"quadrilateral ABCD is similar to quadrilateral QRST"
`(rs)/(bc) (?)/(dc)`

Answer 1

Let's take the ratio of the sides

Using proportion,

5/10 = 4/x

cross-multiply

5x = 40

Divide both-side of the equation by 5

x = 8