2025Q2(iii)(b)Similarity (With Applications to Maps and Models)

NumericalEasy1 mark

2(iii)

In ΔABC, ∠ABC = 90°, AB = 20 cm, AC = 25 cm, DE is perpendicular to AC such that ∠DEA = 90° and DE = 3 cm as shown in the given figure.

Figure for this question

Find the lengths of BC, AD and AE.

Topic: Similarity / scale factor

Previous-year question practice database

Answer

Exam answer

BC = 15 cm, AD = 5 cm, AE = 4 cm.

Explanation

BC=√(25²−20²)=15. From similarity AB/AE=AC/AD=BC/DE=15/3=5, giving AE=4 and AD=5.

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