Saved Bookmarks
| 1. |
The perimeter of a rhombus is 100 cm and one of the diagonals is 40 cm. Then, the area of the rhombus in square centimeters |
|
Answer» now in a rhombus each side is equal. LET each side = X cm. We have: 4X=100 X=100/4 X=25cm Now let one of the DIAGONAL be = Y cm and the other is 14 cm(GIVEN) See, this figure: AB=25cm AO=AC/2(Diagonalbisecteachother) AO=14/2=7cm BO=BD/2 BO=Y/2cm IntriangleAOB AngleAOB=90Degree(Diagonalsareperpendicular) AO2+BO2=AB2(PythagorasTheorum) 72+(Y/2)2=252 49+(Y2)/4=625 (Y2)/4=625–49=576 Y2=576∗4 Y=24∗2 Y=48cm Y/2=24cm Now we know area of Rhombus = 4*(Area of triangle AOB) AreaofTriangleAOB=(1/2)∗AO∗BO =(1/2)∗24∗7 =12∗7 =84sq.cm AreaofRhombus=4∗84 =336sq.cm plzz follow me |
|