A square with a side length of 8.0 cm is rolled up, without overlap, to form the lateral surface of a cylinder.

What is the radius of the cylinder to the nearest tenth of a centimeter?

Ex. 1 – Released Item from 2007 NECAP

Ex 2. Find the Surface Area

13 in

5 in

12 in

4 in

11.4: Surface Area of Pyramids and Cones

p.599-606GSE’s

Primary

M(G&M)–10–6 Solves problems involving perimeter, circumference, or area of two dimensional figures (including composite figures) or surface area or volume of three

Secondary

M(G&M)–10–2 Makes and defends conjectures, constructs geometric arguments, uses geometric properties, or uses theorems to solve problems involving angles, lines, polygons, circles, or right triangle ratios (sine, cosine, tangent) within mathematics or across disciplines or contexts (e.g., Pythagorean Theorem, Triangle Inequality Theorem)

Pyramid: Lateral faces are triangles that share a common vertex.

(l)Slant Height: height of a lateral face

Surface Area of a Regular Pyramid:

PlBAS2

1..

Area of Base Perimeter of Base

Slant height

PlAL2

1..

Lateral Area of a Regular Pyramid:

Find the surface areaof the Regular Pyramid

Find the Lateral Area of the regular pyramid

Cone: - base is a circle - has a vertex

S.A of a Right Cone

lrBSA

or

PlBAS

2

1..

Why are these two equations the same?

L.A. = ?

Find the Surface Area

Find the Lateral area

An entire grain silo needs to be painted with a rust proof paint. How many gallons of paint will need to be purchased ?

[1 gallon of paint = 300 sq feet]

10 ft

40 ft

10 ft

The circumference around the silo was approximated to be 63 ft

warm-up

A right rectangular prism has a Lateral Area of 864 square meters.

• Its length is five times its width

• Its height is twice its width

• Find its Surface Area

ASSIGNMENT