What is the length of an altitude of an equilateral triangle of side 8cm?

(a) 2√3cm   (b) 3√3 cm   (c) 4√3 cm   (d) 5√3 cm

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Question 36 What is the length of an altitude of an equilateral triangle of side 8cm? (a) 2√3cm (b) 3√3 cm (c) 4√3 cm (d) 5√3 cm Let CD be altitude of equilateral triangle Δ ABC Given Side of equilateral triangle = a = 8 cm Now, Area of equilateral triangle = √𝟑/𝟒 𝒂^𝟐 = √3/4 × 8^2 = √3/4 × 64 = 16√𝟑 cm2 Also, Area of equilateral triangle = 1/2 × Base × Height 16√3 = 1/2 × AB × CD 16√𝟑 = 𝟏/𝟐 × 8 × CD 16√3 = 4 × CD (16√3)/4 = CD 4√3 = CD CD = 4√𝟑 cm So, the correct answer is (c)

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo