<span>The sum of the
angle of a triangle is 180 degrees. It is mentioned that Hannah drew a pattern
of equilateral triangles. Equilateral triangle has three equal sides. Also, its
angles are the same, having 60 degrees at each corner of the triangle. The answer
is a. Letter b does not qualify to be an equilateral triangle because 120
degrees times 3 is greater than 180 degrees. Letter c and d exceeds the total
number of angles at 180 degrees.</span>
