If the side of an equilateral triangle is 2 cm, then find the area and the altitude of the triangle.
- AOption (a)
Area = 3/2 cm2 and altitude = √3 cm
- BOption (b)
Area = 2/3 cm2 and altitude = √3 cm
- COption (c)
Area = √3 cm2 and altitude = 2/3 cm
- DOption (d)
Area = √3 cm2 and altitude = √3 cm
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Correct answer
Area = √3 cm2 and altitude = √3 cm
Why this answer is correct
Shortcut Trick
For an equilateral triangle with side a = 2 cm:
Area = (√3 ÷ 4) × a2 = (√3 ÷ 4) × 22 = √3 cm2
Altitude = (√3 ÷ 2) × a = (√3 ÷ 2) × 2 = √3 cm
∴ The correct answer is Area = √3 cm2 and altitude = √3 cm.
Alternate Method
Given: Side (a) of the equilateral triangle = 2 cm.
Formula Used:
- Area of equilateral triangle = (√3 ÷ 4) × a2
- Altitude (h) of equilateral triangle = (√3 ÷ 2) × a
Calculations:
⇒ Area = (√3 ÷ 4) × (2)2
⇒ Area = (√3 ÷ 4) × 4
⇒ Area = √3 cm2
⇒ Altitude (h) = (√3 ÷ 2) × 2
⇒ Altitude (h) = √3 cm
∴ The correct answer is Area = √3 cm2 and altitude = √3 cm.
Additional Information
Perimeter of Equilateral Triangle
The total boundary length is given by P = 3 × a, where a is the side length.
Inradius and Circumradius
For an equilateral triangle, Inradius (r) = a ÷ (2√3) and Circumradius (R) = a ÷ √3. Note that R = 2r.
Area in terms of Altitude
The Area can also be calculated if altitude h is known using the formula: Area = h2 ÷ √3.













