Question

The height of an equilateral triangle measures 9 cm. Find its area correct to 2 places of decimal. (Take V3 = 1.732.)
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Answer 1

Given:-

• Height of an equilateral triangle is 9 cm.

To find:-

• Area upto 2 places of decimal.

Solution:-

Let each side of the equilateral triangle be x.

Then,

⇢ √3/2 × side = 9

⇢ √3/2 × x = 9

⇢ x = 9 × 2/√3

⇢ x = 18/√3

⇢x = 6√3cm

◕ Side of equilateral triangle = 6√3cm.

Side of equilateral triangle = 6√3cm.

Area of equilateral triangle is √3/4 side²

➝ √3/4 × (6√3)²

➝ √3/4 × 36 × 3

➝ √3/4 × 108

➝ √3 × 27

➝ 27√3

➝ 27 × 1732/1000

➝ 46.764

➝ 46.76 [upto 2 decimal]

∴ 46.76cm²