Krishna
0

Step 1: Understand the question and note down the given values

Step 2 : Select the appropriate theorem using the given data.

THEOREM: (Basic proportional theorem)

If a line is drawn parallel to one side of a triangle to intersect

the other two sides in distinct points, then the other two sides are divided

in the same ratio.

Given : In ∆ABC, DE || BC which intersects sides AB and

AC at D and E respectively.

So, \frac{AD}{DB} = = \frac{AE}{EC} = \frac{3}{5}

Step 3: Find the unknown lengths (AE) by using the basic proportional theorem

EXAMPLE:   \frac{AE}{EC} = \frac{3}{5}  [since ( \frac{AD}{DB} = = \frac{AE}{EC} ]

We can write  EC =  AC - AE substitute this in the above equation

\frac{AE}{AC - AE} = \frac{3}{5}

Plugging the AC = 5.6(given) in the above equation

\frac{AE}{5.6 - AE} = \frac{3}{5}

5AE = 3 (5.6 - AE)

5 AE + 3 AE = 3(5.6)

AE = \frac{16.8}{8}

AE = 2.1 cm