Advertisements
Advertisements
प्रश्न
In the given figure, AD = 13 cm, BC = 12 cm, AB = 3 cm and angle ACD = angle ABC = 90°. Find the length of DC.

Advertisements
उत्तर
Given :
∆ ACD = ∠ABC = 90°
and AD = 13 cm, BC = 12 cm, AB = 3 cm
To find : Length of DC.

(i) In right angled ∆ ABC
AB = 3 cm, BC = 12 cm
According to Pythagoras Theorem,
(AC)2 = (AB)2 + (BC)2
(AC)2 = (3)2 + (12)2
(AC) =`sqrt(9+144)=sqrt153` cm
(ii) In right angled ∆ ACD
AD = 13 cm, AC =`sqrt153`
According to Pythagoras Theorem,
DC2 = AB2 − AC2
DC2= 169 − 153
DC = `sqrt16` = 4 cm
∴ Length of DC is 4 cm
APPEARS IN
संबंधित प्रश्न
In an equilateral triangle ABC, D is a point on side BC such that BD = `1/3BC` . Prove that 9 AD2 = 7 AB2
Tick the correct answer and justify: In ΔABC, AB = `6sqrt3` cm, AC = 12 cm and BC = 6 cm.
The angle B is:
In the given figure, ABC is a triangle in which ∠ABC> 90° and AD ⊥ CB produced. Prove that AC2 = AB2 + BC2 + 2BC.BD.

Identify, with reason, if the following is a Pythagorean triplet.
(10, 24, 27)
In the given figure, M is the midpoint of QR. ∠PRQ = 90°. Prove that, PQ2 = 4PM2 – 3PR2.

A right triangle has hypotenuse p cm and one side q cm. If p - q = 1, find the length of third side of the triangle.
Each side of rhombus is 10cm. If one of its diagonals is 16cm, find the length of the other diagonals.
From a point O in the interior of aΔABC, perpendicular OD, OE and OF are drawn to the sides BC, CA and AB respectively. Prove that: AF2 + BD2 + CE2 = OA2 + OB2 + OC2 - OD2 - OE2 - OF2
Find the unknown side in the following triangles
Two squares having same perimeter are congruent.
