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Heron’s Formula — Maths STD 9 — Question

Gujarat BoardEnglish MediumSTD 9MathsHeron’s Formula1 Mark
MCQ
The area of a triangle whose sides are $12\ cm, 16\ cm$ and $20\ cm$ is:
  • A
    $320\ cm^2$
  • ✓
    $96\ cm^2$
  • C
    $72\ cm^2$
  • D
    $240\ cm^2$
✓

Answer

Correct option: B.
$96\ cm^2$

Here, $\text{s}=\frac{12+16+20}{2}=24\text{cm}$
Area of triangle $=\sqrt{\text{s}(\text{s}-\text{a})(\text{s}-\text{b})(\text{s}-\text{c})}$
$=\sqrt{24(24-12)(24-16)(24-20)}$
$=96\text{sq.cm}$

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