Question

In a triangular field having sides 30 m, 72 m and 78 m , the length of the altitude to the side measuring 72 m is

• A. 25 m
• B. 28 m
• C. 30 m
• D. 35 m

Answer 1

The correct option is C 30 m

$s=\frac{30+72+78}{2}=\frac{180}{2}=90$
$\therefore$ Area of $\Delta =\sqrt{90(90-30)(90-72)(90-78)m^2}$
$=\sqrt{90\times 60\times 18\times 12m^2}=1080m^2$
Area of the $\Delta$ with bae ( 72 m)
$=\frac{1}{2}\times 72\times altitude=1080$
$\therefore$ Required length of altitude =$\frac{1080\times 2}{72}=30m$