KnowledgeBoat Logo
|

Mathematics

If BC = 12 cm, AB = 14.8 cm, AC = 12.8 cm, the perimeter of quadrilateral BCYX is :

If BC = 12 cm, AB = 14.8 cm, AC = 12.8 cm, the perimeter of quadrilateral BCYX is : Mid-point Theorem, Concise Mathematics Solutions ICSE Class 9.
  1. 31.8 cm

  2. 15.9 cm

  3. 29.8 cm

  4. 32.8 cm

Mid-point Theorem

32 Likes

Answer

From figure,

X and Y are the mid-point of AB and AC respectively.

∴ BX = AB2=14.82\dfrac{AB}{2} = \dfrac{14.8}{2} = 7.4 cm and CY = AC2=12.82\dfrac{AC}{2} = \dfrac{12.8}{2} = 6.4 cm.

By mid-point theorem,

The line segment joining the mid-points of any two sides of a triangle is parallel to the third side and is equal to half of it.

In △ ABC,

∴ XY = 12BC=12×12\dfrac{1}{2}BC = \dfrac{1}{2} \times 12 = 6 cm.

Perimeter of BCYX = BC + CY + XY + BX = 12 + 6.4 + 6 + 7.4 = 31.8 cm

Hence, Option 1 is the correct option.

Answered By

24 Likes


Related Questions