Question

The ratio of two adjacent sides of a parallelogram is $3:4$ Its perimeter is $105$ cm Find its area if altitude corresponding to the larger is $15$ cm

• A. $900$ $c{m}^2$
• B. $600$ $c{m}^2$
• C. $300$ $c{m}^2$
• D. $450$ $c{m}^2$

Answer 1

The correct option is D $450$ $c{m}^2$

Perimeter of parallelogram$=2(l+b)$

$\Rightarrow 2(l+b)=105\Rightarrow 2(3x+4x)=105$

$\Rightarrow 14x=105\Rightarrow x=7.5$

$\therefore$ Sides of parallelogram are: $3\times 7.5=22.5㎝$ and $4\times 7.5=30㎝$

Area of parallelogram=base $\times$ altitude$=30\times 15=450㎠$