GeoBlog 5th Period

Equations:
V= volume      B= area of the base    h= height      r= radius
Volume of a Pyramid- V=1/3Bh
Volume of a Cone- V=1/3πr2h
Example 1
V=1/3(BxH)
V= 1/3 (8×8)(6.5)
V=1/3(64)(6.5)
V=138.67 or 138 2/3 m3
Example 2
This is a 30-60-90 triangle so in order to find the height we multiply the long leg by √3 the sh.leg.
 
V=1/3π r2h
V= 1/3π(92)(9√3)
V= 1/3π(81)(9√3)
V= 243π√3 m3
By Amanda C
 
 

[Read more]

First, V=volume, B=base area, H=prism height, r=radius, and h=cylinder height
 
The volume of a three-dimensional figure represents how many cubed units can fit into the figure. To find the volume of a prism, multiply the base area times the prism height( V=BH ).
Example 1:V=BH
 The base area would be base times height since the base is a [...]

[Read more]

                               SA=2B+PH
SA=surface area
B=area of base
P=perimeter of base
H=height of prism
 

Ex. 1
SA=2B+PH
SA=2*36+24*12
SA=72+288
SA=360 units^2

SA=2B+PH
SA=2*48+32*10
SA=96+320
SA=416 units^2
 
~posted by: EliseG~

[Read more]

Perimeter=sum of all the sides
Area for a parallelogram= base * height

Ex. 1
P=10+10+5+5=30
Before finding area you must find height. Since this “has” a 30-60-90 triangle(just move the line over to where one side meets a vertex) then:
leg=sq.r.3 * short leg
h= sq.r.3 * 5
h=5(sq.r.3)
therefore:
A= b * h
  =5 * 5(sq.r. 3)
 =25(sq.r. 3)ft. squared
Ex. 2
Determine type of quadrilateral [...]

[Read more]

(can’t figure out how to do the ’square root’ sign, so I am going to use’{ }’.)
(also, ^ means ’squared’)
 
Deriving Formula
ex. radius=4, center= (3,2)
4= {(x-3)^+(y-2)^}
(x-3)^+(y-2)^=4^
 
Formula
(x-h)^+(y-k)^=r^
 
Hope this helps clarify any questions.
~George~
 

[Read more]

Arc Length
 24/360*8pi = 4pi/9
Formula=arc/360 * D(pi)
 
Area of Sector
24/360*4^2(pi) = 8pi/9
Formula=arc/360 * pi(r^2)
 
Probability
30/360 =1/12
Formula=possible/total
By Melinda B
 

[Read more]

Relationship:
J is perpendicular to K
Theorem:
A radius drawn to a point of tangency is perpendicular to the tangent.  K is the radius and J is the tangent.

Relationship:
Mk is congruent to ML
Theorem:
Tangents from the same ext. pt. are congruent.
These theorems should be pretty easy if you don’t think too hard!
-Katherine H.

[Read more]

Relationship-KxL=MxN
** If 2 chords intersect, then the product of their segments are equal
 

Relationship- FHxFG=FJxFI
** if 2 secants are drawn from the same pt the ext. section times the secant equals the ext. section times the secant

Relationship- BExBD=BC sqr
** If a tangent and a secant are drawn from the same pt the the secant times the [...]

[Read more]

Hey. The theorems really aren’t that hard. The theorems we learned in class are great study tools and easy to comprehend. Here’s the first one:
 1.
 
Relationship
a=1/2 b
2a=b
b/a=2
Theorem
**Radius equals is half of the diameter.
2.

Relationship
c=d
arcYZ=arcWX
Theorem
**Congruent chords form congruent arcs.
3.

Relationship
SR perpendicular to TU
e=f
arcSU=arcUR
arcST=arcRT
Theorem
**If a chord is perpendicular to a diameter, then the diameter bisects the chord and its arc.
4.

Relationship
c=d
segmentNO=segmentQP
Theorem
**Congruent [...]

[Read more]

Cirlce- the set of all points in a plane equidistance from a given point, the center
Chord- a segment with endpoints on a circle
Diameter- a chord that runs through the center of the a circle
Radius- segment with one endpoint on the circle and the other on the center
Circumference- distance around a circle
Circumference=Pi(diameter)
c=Πd
c=2Πr

[Read more]