The length and width of the screen of the tv set are in the ratio 16: 9. if the perimeter of the screen is 180cm find its length and width

Let
x> the length of the screen of the TV
y> the width of the screen of the TV

we know that
perimeter of the screen=2*[x+y]
perimeter=180 cm
180=2*[x+y]> 90=x+y> equation 1

x/y=16/9>x=(16/9)*y> equation 2

substitute the equation 2 in equation 1
90=[(16/9)*y]+y> (25/9)*y=90> y=32.4 cm
x=(16/9)*32.4> x=57.6

the answer is
the length of the screen of the TV is 57.6 cm
the width of the screen of the TV is 32.4 cm

The density of the cube is 40