Question

D and e are the midpoint of side ab and ac of a triangle ABC are respectively and BC 6 if De parallel BC then the length of the de is

Answer 1

Step-by-step explanation:

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=8 cm.

Using the basic proportionality theorem, we have

AB

AD

=

AC

AE

=

BC

DE

⇒

AB

AD

=

AC

AE

⇒

15

6

=

AC

8

⇒6AC=15×8

⇒6AC=120

⇒AC=

6

120

=20

Hence, AC=20 cm.

Answer 2

DE // BC (Given)

If DE is parallel to BC then

$de = \frac{1}{2} \times (bc)$

$= 6\times \frac{1}{2} \\ \\ = \frac{6}{2} \\ \\ = \frac{3}{1} \\ \\ =3$

The answer is 3