Braelyn Is writing including to officiate rectangle with a width equal to half the length she knows the perimeter is equal to 18 units and needs to find the length and width of the rectangle

Length= 6 Width= 3

the formula to find the perimeter in a rectangle is 2(L+W)=perimeter
they gave us the perimeter so we substitute is into the equation:
2(L+W)=18
substitute the W by 1/2L
u will end up with 2(L+1/2L)=18
distribute the 2 and u will get:
2L+1L=18 which is 3L=18 and L=6
we know that the width is half the length so W=1/2(6) so W=3