Geometry
Notes – Lesson 10.3 and 10.5
Name __________________________________
Regular Polygons: All Sides - __________ All Angles - __________ and Convex
The radius is the distance from the center to a ________________.
The apothem is the perpendicular distance from the center to a _______________.
To find the measure of a central angle: ___________  ___________________________________
Find the measurements of the central angles.
Each regular polygon has radii and an apothem as shown. Find the measure of each numbered angle.
Area of a REGULAR Polygon
Formula: _________________
where a = _______________ and
Examples: Given apothem and side. Round answers to the nearest tenth.
p = ______________________
Special Right Triangles Rules.
45-45-90
30-60-90
Examples: Find the Areas Using special right triangle rules. Round answers to the nearest tenth.
Trigonometry Option: Find the Areas using SOHCAHTOA.
A regular octagon with a side of 8 cm
Solve either using Special right triangles or Trig.
A regular dodecagon with a apothem of 20
A regular hexagon with a side of 22 in