The perimeter of an equilateral triangle is 21cm, find its length

Radii ok and nl are perpendicular to om because of the radius-tangent theorem. by definition of perpendicular, angles kom and lnm are right angles. this means that triangles kom and lnm are right triangles. angle lmn is common to both right triangles, so by the triangles kom and lnm are similar.

What situation is an example of an observational study

Construct the graph that models the given situation