Step-by-step explanation:
look at the picture !
she has to paint actually 6 rectangles :
the 3 tops of the 3 stairs.
and the 3 vertical front boards (the front of each step of the stairs).
what is the area of these rectangles ? summing up all 6 - that is the surface area to be painted.
each top rectangle is clearly
82×19 (19 cm deep) = 1558 cm²
each front board is
82×12 (12 cm high) = 984 cm²
so, in total we have
3×1558 + 3×984 = 4674 + 2952 = 7626 cm²
as surface area to be painted.
58 plus tip of .20
so
58 times 0.2 = 11.6 is the tip
now we add tax (Presuming we son't tax the tip)
58 times 0.07 = 4.06 the tax
so its
58 + 11.6 + 4.06 = $73.66 total cost
4. because it is reduced and the simplest to understand
