Angle Basics
The point where two rays meet to form an angle.
Vertex
Two angles that add up to 90°.
Complementary angles
The sum of all interior angles in a triangle.
180°
50% of 200.
100
A percent taken off the original price.
Discount
An angle that measures exactly 90°.
Right Angle
Two angles that add up to 180°.
Supplementary Angles
Formula for sum of interior angles of an n-sided polygon.
(n − 2) × 180°
Convert 0.25 to a percent.
25%
A percent added to a purchase price by the government.
Sales Tax
An angle less than 90°.
Acute Angle
Two angles that share a vertex and a side.
Adjacent Angles
The sum of exterior angles of any polygon.
360°
What percent is 15 out of 60?
25%
If an item costs $50 and is 10% off, what’s the new price?
$45
An angle more than 90° but less than 180°
Obtuse Angle
Equal angles in matching positions when a transversal crosses two parallel lines.
Corresponding Angles
The measure of each interior angle of a regular hexagon.
120°
Increase 150 by 20%.
180
You earn 5% commission on $2,000 in sales. How much do you make?
$100
The unit angles are measured in is called?
Degrees
Opposite angles formed when two lines cross; they are always equal.
Vertical Angles
The number of sides of a regular polygon with each interior angle 150°
12 sides
Decrease 80 by 15%.
68
Simple interest on $1,000 at 4% for 3 years.
$120