Question

The perimeter of equilateral triangle is 18cm then hight of e

Answer 1

√[(6)²-(3)²]=√[36-9]=√27=3√3cm

Answer 2

HEYA !

Let ∆ABC is that equilateral triangle
[ See above Figure ]

Given that,
Perimeter of triangle is 18 cm

Perimeter = 18 cm

3 × Side = 18 cm

→ Side = 6 cm

→ AB = BC = AC = 6 cm

Now ,

An altitude AD is drawn from A
[ This is height of ∆ABC ]

Then,

BD = DC = 3 cm

Now,

Using Pythagoras theorem in ∆ACD ,
We have

AC² = AD² + DC²

6² = AD² + 3²

36 = AD² + 9

→ AD² = 36 - 9

→ AD = √27

→ AD = 3√3 cm

Hence,

The height is 3√3 cm

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