Answer:
DE ≈ 3.9 cm
Explanation:
since the triangles are similar then the ratios of corresponding sides are in proportion, that is
=
( substitute values )
=
( cross- multiply )
17.2 × DE = 8.4 × 8 = 67.2 ( divide both sides by 17.2 )
DE = 3.9 cm ( to the nearest tenth )