An equilateral triangular sheet is formed by joining 9 equilateral triangular sheets each of area \(9\sqrt 3 \) cm2. What is the height of the bigger triangular sheet?
An equilateral triangular sheet is formed by joining 9 equilateral triangular sheets each of area \(9\sqrt 3 \) cm2. What is the height of the bigger triangular sheet? Correct Answer <span class="math-tex">\(9\sqrt 3 \,{\rm{cm}}\)</span>
Given:
Area of each smaller equilateral triangle = 9√3 cm2
Concept Used:
Area of equilateral triangle = √3a2/4
Height of equilateral triangle = √3a/2
Where, a = side of the equilateral triangle
Calculation:
[ alt="F1 Savita Defence 11-5-22 D13" src="//storage.googleapis.com/tb-img/production/22/05/F1_Savita_Defence_11-5-22_D13.png" style="height: 188px; width: 177px;">
Let the side length of each smaller triangle be a cm
Since the area of each smaller equilateral triangle = 9√3 cm2
So, √3a2/4 = 9√3
⇒ a = 6 cm
So, the side of bigger equilateral triangle ABC = 6 × 3 = 18 cm
So, Height AD of the bigger equilateral triangle = (√3 × 18)/2 = 9√3 cm
∴ The required height of the bigger equilateral triangle is 9√3 cm.