6. The length and width of a rectangular field are in the ratio 3:2. If the area of the field is 150 square units find its perimeter

Question

6.	The length and width of a rectangular field are in the ratio 3:2. If the area of the field is 150 square units find its perimeter

anonymous · Answer

$$l=3a$$$$w=2a$$where length is l, and width is w.  You can see then that length to width is$$\frac{l}{w}=\frac{3a}{2a}=\frac{3}{2}$$
You know$$A=lw $$so$$150=(3a)(2a)=6a^2$$That is$$a^2=\frac{150}{6}=25$$so$$a=\pm 5$$Since we're dealing with length and width, we take the positive solution only (i.e a=5).  So, the perimeter is$$p+2l+2w=2(3a)+2(2a)=10a=10(5)=50$$units.

anonymous · Answer

^^ $$p=2l+2w$$