Question

Find the size of the angle of a parallelogram if one angle is ${20}^0$ less than twice the smallest angle

Answer 1

Let the smallest angle be $x^o$.

Then, the other angle will be $(2x-20{)}^o.$

W e know that, sum adjacent angles of parallelogram are supplementary.

$\therefore$ $x+(2x-{20}^o)={180}^o$

$\Rightarrow$ $3x-{20}^o={180}^o$

$\Rightarrow$ $3x={200}^o$

$\Rightarrow$ $x=\frac{{200}^o}{3}$

$\therefore$ $x={66.7}^o$

$\Rightarrow$ Other angle $=2\times {66.6}^o-{20}^o={113.3}^o$