Download 10-5 practice worksheet

Name
Class
Date
Practice
Form K
10-5 Trigonometry and Area
Find the area of each regular polygon. Round your answers to the nearest tenth.
1. pentagon with side length 8 in.
To start, find the measure of a central angle.
Then use trigonometry to find a.
The measure of the central angle of the regular
1
360
pentagon is
=
so, mC  ·
=
2
5
4
4
4
=
= ?
tan 36° = ; a =
a
tan 36
?
2. hexagon with side length 9 m
.
3. decagon with radius 4 mm
4. octagon with radius 10 cm
Find the area of each triangle. Round your answers to the nearest tenth.
5.
To start, write the SAS formula, then substitute
given values into the formula.
1
A  bc (sin A)
2

6.
1
2
(sin 92°)
7.
Name
Class
Date
Practice (continued)
Form K
10-5 Trigonometry and Area
8. ABCDEFGH is a regular octagon with center X and radius 5 cm.
Find each measure to the nearest tenth.
a. mFXE
b. mYXE
c. XY
Find the perimeter and area of each regular polygon to the nearest tenth.
9.
10.
The polygons are regular polygons. Find the area of the shaded region to the
nearest tenth.
11.