Sides AB and BE of a right triangle, right angled at B are of lengths 16 cm and 8 cm respectively. The length of the side of largest square FDGB that can be inscribed in the triangle ABE is

(a) 13/100  (b) 13/10    (c) 10/13   (d) 100/13

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Question 34 Sides AB and BE of a right triangle, right angled at B are of lengths 16 cm and 8 cm respectively. The length of the side of largest square FDGB that can be inscribed in the triangle ABE is (a) 13/100 (b) 13/10 (c) 10/13 (d) 100/13 Let FDGB be a square with side x cm Now, For parallel lines FD and CE with transversal AE ∠ ADF = ∠ AEB Also, since FDGB is a square ∠ AFD = 90° & ∠ DGF = 90° In Δ AFD and Δ DGF ∠ AFD = ∠ DGF ∠ ADF = ∠ AEB ∴ Δ AFD ~ Δ DGF Since sides in similar triangle are proportional 𝐴𝐹/𝐷𝐺=𝐹𝐷/𝐺𝐸 (𝟏𝟔 − 𝒙)/𝒙=𝒙/(𝟖 − 𝒙) (16 − x) (8 − x) = x2 16 (8 − x) − x (8 − x) = x2 128 − 16x − 8x + x2 = x2 128 − 16x − 8x = 0 128 − 24x = 0 128 = 24x 24x = 128 x = 128/24 x = 𝟏𝟔/𝟑 cm So, the correct answer is (b)

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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, Social Science, Physics, Chemistry, Computer Science at Teachoo.