NumericalModerate2 marks
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.
If BCED represents a plot of land on a map whose actual area on ground is 576 m², then find the scale factor of the map.
Topic: Similarity / scale factor
Previous-year question practice database
Answer
Exam answer
Scale factor = 1 : 200.
Explanation
Map area BCED = area ΔABC − area ΔAED = 150−6=144 cm². Actual area 576 m² =5,760,000 cm². Area scale =144:5,760,000=1:40,000, hence linear scale =1:200.
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