Question

In ∆ ABC DE // BC. If AD = 5 cm, BD = 7 cm and AC = 18 cm find the length of AE.

Answer 1

Answer:

In triangle ABC

DE parallel BC

AD/AB = AE/AC (by corollary of b. p. t )

5/12 = AE/18 (AB=AD+BD=5+7)=12cm

12AE = 5*18

AE =5*18/12

AE =15/2

AE = 7.5cm

Answer 2

Answer:

AE=7.5cm

Step-by-step explanation:

It is assumed that the point D lies on AB and the point E lies on AC.

Draw a figure with given data

Let's AE=Xcm

theEC=(18-X)cm, AD=5cm, BD=7cm

we have AE/EC=AB/BD.....(By Proportionality Theorem)

X/18-X=5/7

7X=5(18-X)

7X=90-5X

7X+5X=90

12X=90

X=90/12

X=7.5cm