Angles Formulas and Notes

Straight Angle

Straight Angle \displaystyle = x = 180 \degree

Acute Angle

Acute Angle \displaystyle = a

\displaystyle a < 90 \degree

Obtuse Angle

Obtuse Angle \displaystyle = x

\displaystyle 90 \degree < x < 180 \degree

Right Angle

Right Angle \displaystyle = x = 90 \degree

Reflex Angle

Reflex Angle \displaystyle = x

\displaystyle 180 \degree < x < 360 \degree

Full Angle

Full Angle \displaystyle = x = 360 \degree

Supplementary Angle

Two angles that have a sum of 180°

\displaystyle a + b = 180 \degree

Complementary Angle

Two angles that have a sum of 90°

\displaystyle a + b = 90 \degree

Consecutive Interior Angles

\displaystyle a + b = 180 \degree

\displaystyle c + d = 180 \degree

Alternate Exterior Angles

\displaystyle a = b

\displaystyle c = d

Alternate Interior Angles

\displaystyle a = b

\displaystyle c = d

Corresponding Angles

\displaystyle a = b, c = d

\displaystyle e = f, g = h

Vertical Angles

When two lines intersect, they form 4 angles. The verical lines are equal in measure.