Question

8. In the adjoining figure, all adjacent sides are at right angles. Find: () the perimeter of the figure. ii) the area enclosed by the figure. D C 7 4 cm 7 cm a tablo find the solution of the​

Answer 1

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 DE∣∣AB,AD=7 cm, CD=5 cm and BC=18 cm.

Using the basic proportionality theorem, we have

CACD

​

= ABDE

​

= CBCE

​

⇒ CACD = CBCE

​

⇒ 125​

= 18CE

​

⇒18×5=12CE

⇒12CE=90

⇒CE= 1290 =7.5

Since CE=7.5 cm, therefore,

CB=CE+EB

⇒18=7.5+EB

⇒EB=18−7.5=10.5

Hence, BE=10.5 cm and CE=7.5 cm.