A
An angle less than 90°
Acute
How many angles does a triangle have?
3
A triangle with all sides equal
Equilateral
A triangle has angles 40° and 60°. The third is ___
80
A shape with four sides
Quadrilateral
An angle equal to 90°
Right angle
The sum of interior angles in a triangle
180
If a triangle has one obtuse angle, what must be true about the others?
They must be acute
A quadrilateral with four right angles
A quadrilateral with four equal sides and four right angles
square
An angle greater than 90° but less than 180°
Obtuse
If one angle in a linear pair is 130°, the other is ___
50
A triangle with one 90° angle
right triangle
If interior angle is 70°, exterior angle is ___
110
Triangle angles: 50°, 60°, ___
70
Two angles that add up to 90°
Complimentary
Angles on a straight line add up to ___
180
A triangle with all different sides
Scalene
An exterior angle equals the sum of the ___
Two opposite interior angles
Sum of interior angles of a quadrilateral
360
Two angles that add up to 180°
Supplementary
Angles opposite each other when two lines cross
Vertical Angles
A triangle with exactly two equal sides
Isosceles
An exterior angle is formed when you ___
Extend one side of a triangle
If an exterior angle is 130°, the two opposite interior angles add to ___
130