3.lengths of adjacent sides of a parallelogram is 3cm and 4cm. find its area?
Answers
Given :
The two sides of a parellogram are 3 and 4 cm respectively
To Find :
The area of the parallelogram .
Solution:-
As it is a parellelogram so its opposite sides must be equal .
Now ,
let , The side AB and DC of the parellelogram be 3 Cm .
and , The side AD and CB of the parellelogram be 4 Cm.
Construction :-
Draw a diagonal AC through the point A to C of it .
Now,
let, AD be the height and CD be the base
so,
By pythagoras theorem ,
AC ² = AD ² + DC ² ( as AC is the hypotenus )
AC² = ( 4)² + ( 3) ²
AC ² = 16 + 9
AC ² = 25
AC = √25
AC = 5 cm
so, The Area of the ΔADC = × base × height sq.unit
= × 4 × 3 cm²
= 2 × 3 cm²
= 6 cm²
Now, Area of the parallelogram ABCD = 2 × AREA OF ΔADC
= ( 2 × 6 ) CM²
= 12 CM²
Therefore , The area of the parallelogram ABCD is 12 cm².