Classifying Triangles and Figures

How are triangles classified?

• equal sides and types of angles

• number of sides and number of angles

• color and size

• angles

A SCALENE triangle has _____________.

• 3 equal sides

• 4 equal sides

• no equal sides

• 2 equal sides

An OBTUSE triangle has _____________.

• 1 obtuse angle

• 2 obtuse angles

• 3 obtuse angles

• no obtuse angles

Which of the following figures is impossible to draw? 

• right scalene triangle

• obtuse equilateral triangle

• right isosceles triangle

• acute scalene triangle 

Which of the following MUST be true for a triangle to be scalene?

• all 3 sides cannot be congruent

• two sides have to be congruent

• all angle measures are less than 90 degrees

• must have 4 congruent sides and angles

I am a triangle with all sides measuring less than 90 degrees. What am I?

• Right triangle

• Scalene triangle

• Acute triangle

• Obtuse triangle

Which statement correctly compares these two triangles?

• Both figures are polygons with all different side lengths and angles.

• Both figures are polygons with one right angle.

• Both figures are polygons with one pair of congruent sides and 2 equal angles.

• Both figures are polygons with 3 obtuse angles.

Which of the following statements supports the fact that an equilateral triangle is also an isosceles triangle?

• They both have at least two congruent sides.

• They are both triangles.

• The sum of all the measures of the angles is 180 degrees.

• All the angles are congruent.

Classify this triangle based on its side lengths and type of angle.

• equalateral, acute

• equilateral, obtuse

• equilateral, right

A sail on a sailboat is a triangle with two sides perpendicular and each side is a different length. What are the two terms that could be used to describe the triangular sail? 

• Isosceles, right

• Isosceles, acute

• Scalene, right

• Scalene, obtuse