Question

triangle ABC is parallel to triangle DEF and AB : DE = 5:3. Find. DE if
AC 12. cm.​

Answer 1

Answer:

ANSWER

The basic proportionality theorem states that if a line is drawn parallel to one side of a triangle and it intersects the other two sides at two distinct points then it divides the two sides in the same ratio.

It is given that AD=6 cm, DB=9 cm and AE=8cm.

Using the basic proportionality theorem, we have

ABAD=ACAE=BCDE⇒ABAD=ACAE⇒156=AC8⇒6AC=15×8⇒6AC=120⇒AC=6120=20

Hence, AC=20 cm.