Basic Angle Classifications
What type of angle is less than 90 degrees
Acute Angle
What are angles on opposite sides of the transversal, inside the parallel lines. They are equal.
alternate interior angles
What is the formula for the sum of the interior angles of any convex polygon?
The sum formula is ( n - 2 ) x 180 where (n) is the number of sides.
How are triangles classified by their side lengths?
Scalene (no equal sides), Isosceles (two equal sides), and Equilateral (three equal sides).
What angle is exactly 180 degrees
Straight Angle
What is angles on opposite sides of the transversal, outside the parallel lines. They are equal.
alternate exterior angles
How do you find the measure of an individual interior angle of a regular polygon?
( n - 2 ) x 180
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n
What is the sum of all the Interior Angles in a triangle.
The interior angles of any triangle always add up to exactly 180 degrees
What angle is between 90 degrees to 180 degrees
Obtuse Angle
What are angles in the same relative position at each intersection. They are equal.
Corresponding angles
What is the sum of the exterior angles of any convex polygon?
The sum of the exterior angles is always exactly 360 degrees regardless of the number of sides.
What is the relationship between the angles of an equilateral triangle?
All three interior angles are completely equal, and each one always measures exactly 60 degrees (180 / 3)
What angle is greater than 180 degrees but less than 360 degrees
Reflex Angle
Angles on the same side of the transversal, inside the parallel lines. They are supplementary (180 degrees)
Consecutive (same-side) interior angles
How many triangles are created when drawing all possible diagonals from a single vertex of an 11-sided polygon (undecagon)
It creates 9 triangles (11 - 2 = 9), which represents the (n - 2) part of the interior angle sum formula.
Can a triangle have two right angles? Explain your reasoning
No. Two right angles would equal 180 degrees (90+90), leaving 0 degrees for the third angle, which is impossible.
what type of angle has to be in a triangle
What are two adjacent angles that form a straight line. They are always supplementary
linear pair
If you know the individual exterior angle of a regular polygon, how can you find its individual interior angle?
Subtract the exterior angle from 180 because an interior angle and its adjacent exterior angle always form a linear pair.
In a triangle, if an exterior angle measures 110 degrees and one remote interior angle is 40 degrees, what is the other remote interior angle?
It is 70 degrees, because the exterior angle equals the sum of the two remote interior angles ( 110 - 40 = 70 )