This document contains notes from a math lesson on geometry. It includes: 1) An assignment that is due on Wednesday and to check if a test was signed; 2) Warm-up problems on fractions, expressions, and perimeter; 3) Definitions of sectors and central angles of circles; 4) Worked examples of sector area problems; 5) Definitions of geometric solids, faces, edges, and vertices; and 6) Homework to define additional geometric shapes.
1. Lesson 40.notebook December 10, 2012
Assignment:
1>Set 40 (evens) Due Wednesday (12/12)
2>Test #5 signed??
1
2. Lesson 40.notebook December 10, 2012
Lesson 40 WarmUp:
1) Write 32% as a decimal and as a reduced fraction.
2) Combine like terms: xyz + yxz zyx x2yz
3) Expand: 4x(2x 9)
10 feet
4) Simplify: 1/9 + 4/6 4/12
5) Find the perimeter: 12 feet
15 feet
2
3. Lesson 40.notebook December 10, 2012
Lesson 40
*sector – a portion of the interior of a circle enclosed
by two radii and an arc (a part of a circle)
*central angle – the angle formed by 2 radii and
determines the fraction of the area of the circle the
sector occupies
FYI...Area of a circle pi times radius squared
x r2
3
4. Lesson 40.notebook December 10, 2012
Examples Lesson 40
pg. 267
A)
B)
C)
4
7. Lesson 40.notebook December 10, 2012
Investigation #4 (vocab):
*geometric solids a 3D geometric figure
*faces a flat surface of a geometric solid
*edges a line segment formed where 2 faces of a geometric solid
intersect
*vertex (vertices) a point where 2 edges of a geometric solid meet
*polyhedron a geometric solid whose faces are polygons
*prism a polyhedron with 2 congruent parallel bases
7
8. Lesson 40.notebook December 10, 2012
*pyramid a type of polyhedron with lateral surfaces that narrow to a
point
*cylinder a geometric solid with 2 parallel bases that are circles
*cone a geometric solid with one circular base that connects to a point
*sphere a smooth curved solid, that has every point the same distance
from its center
8
