warm up find the lateral and surface area of the following figures. leave your answers in terms of...
TRANSCRIPT
WARM UP
Find the Lateral and Surface Area of the following figures. Leave your answers in terms of π
10 minutes
End
TODAY’S OBJECTIVE
Students will be able to find the surface area of pyramids, cones, and spheres
PYRAMID
Definition: A Pyramid is a polyhedron with one polygonal base and triangular lateral faces that meet at a common vertex
The Altitude of a Pyramid (or height) is the perpendicular segment from the vertex to the base.
The SLANT HEIGHT (L) is the length of the altitude of a lateral face of the pyramid
PYRAMID FORMULAS
EX6: FIND LATERAL AND SURFACE AREAS
LA =
SA =
EX 7: FIND LA AND SA
LA =
SA =
CONES
Definition: A cone is like a pyramid but has a circle base. The Altitude (or height) is the perpendicular distance from the vertex to the base. The slant height is the distance from the vertex to a point on the edge of the base.
CONE FORMULAS
EX 8: FIND LA AND SA
LA =
SA =
EX 8: FIND LA AND SA
LA =
SA =
REGULAR TETRAHEDRON• A Tetrahedron is a polyhedron composed
of four congruent, equilateral triangles
SURFACE AREA OF A REGULAR TETRAHEDRON
A Net is a two-dimensional pattern that can be folded into a 3-D figure (We’ll look at more tomorrow)
Lets look at a net for a regular tetrahedron.
How can we find the surface area of a regular tetrahedron?
or
EXAMPLE
Calculate the surface area of a regular tetrahedron with an edge of 5cm
SPHERE
Definition: A Sphere is the set of all points in space equidistant from a given point (the center)
Definition: The Great Circle is the largest cross section (circle) of a sphere and shares the same radius and center as the sphere
Center
Great Circle
SURFACE AREA OF A SPHERE
Find the Surface Area of the following spheres in terms of π
Ex 1: r = 14
Ex 2: d = 12
Ex 3: C = 36π
Ex 4: C = 52π
CLASSWORK
Arrange desks in groups
As a group, complete page 3 of Unit 10 packet (skip #1 of right side) and do SA of 1-6 on page 5
Be prepared to have your work displayed on doc cam!
HOMEWORK
1. Complete the left side of page 3 and number 3 from the right side.
2. Find the Surface Area of each sphere on page 5 (1-6)
QUIZ TOMORROW!