A clear sight triangle is the triangle formed on corner lots between points on the edges of street road pavement 35 feet from the intersection of both streets. Within that area, no fence, wall, ornamental gate or portal, bushes, shrubbery or stored material shall be permitted higher than two feet above the average finished grade of the lot. Trees shall be permitted within the area only if maintained and trimmed so that no branches or foliage are less than eight feet above the average finished grade of the lot.