Step by step explanation :
❃
![\underline{ \underline{ \sf{Given} }}:](https://img.qammunity.org/2022/formulas/mathematics/high-school/7n5kshb8t1pctnylo62b4mz9ngrrd3oxdx.png)
- Base length ( b ) = 21 cm
- Vertical height ( h ) = 9 cm
- Slant height = 12 cm { Ignore the slant height as it is not required while finding the area }
❃
![\underline{ \underline{ \sf{To \: find}} }:](https://img.qammunity.org/2022/formulas/mathematics/high-school/y05dbbsmi5bfmm6m9w5eiqlyhmx9np7akz.png)
- Area of the given parallelogram
✑
![\bold{ \red{ \boxed{ \sf{Area \: of \: a \: parallelogram \: = bh}}}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/12cjsc85x9839c6ezj5h65yuyq6xbzioq9.png)
Substitute the known values :
⇝
![\sf{21 cm * 9 \: cm}](https://img.qammunity.org/2022/formulas/mathematics/high-school/kjpjy6ymuow7ft2ruman42pszhlzyv97fc.png)
⇝
![\boxed{ \bold{ \sf{189 \: {cm}^(2) }}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/1qz365izbo8pj92lnfuuwpo3yyinjilc1r.png)
☥
![\boxed{ \boxed{ \tt{Our \: final \: answer : \bold{ 189 \: {cm}^(2) }}}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/hum6vdp469ml97gl91jnm9i8dsgc38ekqh.png)
Hope I helped ! ♡
Have a wonderful day / night ツ
▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁