Question

Triangles ABC and DEF are similar. If AB=4, BC = 5 cm, EF = 15 cm, then what is the value of DE? (THIS QUESTION FROM TRIANGLES CLASS 10)

Answer 1

BC/EF = AB/DE
=> 5/15 = 4/DE
=> DE= 12

Answer 2

Answer:

usin similarity of triangles

4/x = 5/15 ie ( ab/de = bc/ef )

x = 4*3

x = 12