ABC is a equilateral triangle of side 2a.find each of its altitude
Answers
the triangle of two side is equal then triangle is equal
Given: ∆ABC is an equilateral triangle with side 2a.
Construction: Draw altitude AD such that AD is perpendicular to BC.
To find: AD
Solution: In ∆ADB and ∆ADC,
AB = AC (Both sides are 2a)
AD = AD (Common side)
<ADB=<ADC (Both 90° as AD
perpendicular to BC)
Hence, ∆ADB ~ ∆ADC (By R.H.S congurancy)
Hence, BD = DC ( By cpct )
BD = DC
BD = DC = 1/2 BC
BD = DC = 2a/2
BD = DC = a
Hence, BD = a
In right ∆ADB,
by using Pythagoras theorem,
(AB)^ = (AD)^ + (BD)^
(2a)^ = (AD)^ + (a)^
4a^ = (AD)^ + a^
4a^ - a^ = (AD)^
3a^ = (AD)^
AD = √3a^
AD = a√3
Thus, the length of altitude AD = a√3
Similarly, CF = BE = a√3