Possible Clues:

• Having sides of different lengths, as a triangle
• Having sides of different lengths, as triangles go
• Like a 3-4-5 right triangle
• Not isosceles or equilateral
• Neither isosceles nor equilateral
• Kind of triangle or muscle
• Having three unequal sides, of a triangle
• Like a sailboat's mainsail
• Like the figure formed by the three circled letters in the upper left
• Like a triangle with sides of different lengths