Question

the diagonals of rhombas are in the ratio 3:4 if its perimeter is 80cm find its area

Answer 1

given ,perimeter of rhombus=80cm

then,side of rhombus=perimeter/4
=80/4=20cm

area of rhombus(square)=side sq.
=(20×20)cm sq.
=400cm sq.

Let the diagonals of rhombus be 3x and 4x
then, Area of rhombus=(1/2×d1×d2)sq. unit
=(1/2×3x×4x)cm sq.
=(6x sq.)cm sq.

Then,6x sq.=400
:x sq.=400/6
:x=uder root 66.7
:x=8.2 (it may be more i gave u as a eg.)

d1=3x=3×8.2=25.6cm
d2=4x=4×8.2=32.8cm

Now ,Area of rhombus=(1/2×d1×d2)sq.unit (now u can find)