If the height of a triangle is increased by 30% and its base is decreased by 20%, then what will be the effect on its area?
Answer & explanation
Correct answer: option 3
30% = \(\frac{3}{10}\)
20% = \(\frac{1}{5}\)
Area of triangle = \(\frac{1}{2}\) × Base × Height
Old New
Height 10 : 13
Base 5 : 4
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Area = 50 : 52
Percentage increase in Area = \(\frac{52 - 50}{50}\) × 100%
= \(\frac{2}{50}\) × 100%
= 4%