That’s ur answer, your welcome
The intersecting secant-tangent theorem says that

where T is the point at which line segment PO touches the circle. Similarly,

so we have

OP is of course as long as itself, and AO and BO are radii of the same circle so they have the same lengths.
This means triangles APO and BPO are congruent, which means angles APO and BPO are congruent, so angle APB is bisected by PO.
Ok let us assume x= the width of the table top
the length is 4 times the width meaning we are multiplying 4 and the width
which is x
length = 4x
your first equation would be the following:
4x+4x+x+x= whatever the perimeter is
if you drew a rectangle it would help you understand the above.
this represents the perimeter of the tabletop because we know the width is x. if you drew the rectangle there wouldn't be 1 width. opposite to the width is another line. same with the length. the length is 4x again there are 2 because in a rectangle there are 2 sets of parallel lines. that is why your equation would be 4x+4x+x+x= whatever the perimeter is- you could simplify this equation and write:
10x= whatever the perimeter is
x basically means 1x but in math we generally don't write that because we tend to write most things in simplest for.
hope this helps :)