Octagon eight lines of reflective symmetry and rotational symmetry of order 8. A regular octagon is represented by the Schläfli symbol {8}. The internal angle at each vertex of a regular octagon is 135° (formula_1 radians). The central angle is 45° (formula_2 radians). The area of a regular octagon of side length "a" is given by In terms of the circumradius "R", the area is In terms of the apothem "r" (see also inscribed figure), the area is These last two coefficients bracket the value of pi, the area of the unit circle. The area can also be expressed as where
Clock angle problem through 360° in 60 minutes or 6° per minute. where: where: The time is 5:24. The angle in degrees of the hour hand is: The angle in degrees of the minute hand is: The angle between the hands can be found using the following formula: where If the angle is greater than 180 degrees then subtract it from 360 degrees. The time is 2:20. The time is 10:16. The hour and minute hands are superimposed only when their angle is the same. 10:54., and 12:00. Clock angle problem Clock angle problems are a type of mathematical problem which involve finding