Q. 104.7( 3 Votes )

# ΔABC is an isosceles triangle with AB = AC = 13 cm and the length of altitude from A on BC is 5 cm. Then, BC = ?

A. 12 cm

B. 16 cm

C. 18 cm

D. 24 cm

Answer :

The given triangle is isosceles so the altitude from the one of the vertex is median for the side opposite to it.

AB = AC = 13 cm

h = 5 cm (altitude)

Δ ABX is a right angled triangle, right angled at X

(AB)^{2} = h^{2} + (BX)^{2} (BX = 1/2 BC)

169 = 25 + (BX) ^{2}

BX = 12

⇒ BC = 24

Rate this question :

How useful is this solution?

We strive to provide quality solutions. Please rate us to serve you better.

Related Videos

Basic Proportionality Theorem42 mins

A Peep into Pythagoras Theorem43 mins

Predominant Proof of Triangles52 mins

NCERT | Strong Your Basics of Triangles39 mins

RD Sharma | Imp. Qs From Triangles41 mins

Quiz | Criterion of Similarity of Triangle45 mins

How to Ace Maths in NTSE 2020?36 mins

R.D Sharma | Solve Exercise -4.2 and 4.345 mins

Champ Quiz | Thales Theorem49 mins

NCERT | Concept Based Questions on Triangles31 mins

Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Expertsview all courses

Dedicated counsellor for each student

24X7 Doubt Resolution

Daily Report Card

Detailed Performance Evaluation