Concepts Pt 2.

Question 1

What’s a parallelagram

Answer 1

equal parallel sides

Question 2

What happens to the the area of a rectangle with a constant perminiter when…

Answer 2

Area increases as L/W become more similar and is maxed when the rectangle is square

Question 3

What;s a trapazoid

Answer 3

unequal parallel sides

Question 4

Don’t assume your polygon is regular instead…

Answer 4

Use n-2 (180º)

Question 5

Equalaterial Triangle

Answer 5

Evey angle is 60º

Question 6

isosceles right triangle

Answer 6

-have 2 equal sides and therefore two equal angles
- has sides 1:1:√2
45-45-90

Question 7

To find the area of a central angle…

Answer 7

try to dind what proportion of the cirecle that area covers, then find total circle area

Question 8

Minor Arc

Answer 8

is the short way around the circle

Question 9

Major Arc

Answer 9

the long way around a circle

Question 10

An inscribed Angle

Answer 10

this is an angle that starts on one side of the circle instead of in the center of the circle.
-It is always 1/2 the central anfle

Question 11

Pathagrean Triples

Answer 11

3, 4, 5
5, 12, 13
8, 15, 17
7, 24, 25

Question 12

The Third Side Rule

Answer 12

any side of a triangle must be greater than the diffrence of the other two sides and less than their sum.

Ex: sides A = 10 B= 13
Side C must be between: 
13+10 = 23
13-10= 3
23 > C > 3

Question 13

Within any triangle, the larger the angle….the ___ the side opposite that angle

Answer 13

the longer the side opposite that angle

Question 14

How are Coordinates writen
A) x, y
B) y, x

Answer 14

A) x, y

Question 15

Is this coordinate on this line? How could you tell?

Answer 15

Plug it in and check!
Ex: 
y = 3x + 5  (8,2)
y = 3(8) + 5
y = 24 + 5
y = 29
Therrfore no

Question 16

Parabolas What does eveything mean?

y = (x-h) ^2 + k

Answer 16

y = (x-h) ^2 + k

• h, k is the location of the vertex
• be very careful of the sign in front of the h! Since H is normally subtracted, a sign flip could mean the vertex sits in the negative colum.

Example
y = (x+3)^2 +3

The vertex is -3, 3

Question 17

What’s the relationship between two perpendicular slopes

Answer 17

Two perpendicular slopes (right angle) have reciprical slopes. If one is 2 then the other is -1/2. (note the negative!)

Question 18

What is 50 as a percent of 30

Answer 18

This means What percent of 30 is 50?

50/30 x 100 = 166%

Question 19

12 is 5% of x

Answer 19

12 = 0.05x

Question 20

With different percent increases make equations

Ex: if K was increased 20%

Answer 20

= k + 02.k

Question 21

X is reduced by 30%

Answer 21

=70%x

Question 22

36 is x% more than 24

Answer 22

36 = 24 + (x%)24 –> 0.5 = x%

Question 23

When writing percents, make sure to write x/100 and not x

Answer 23

This is so you know that the final number is 300% and not 3%

Question 24

When using percent diffrence, be very careful of what your original percent is
-Ex: x is what percent more than y?

Answer 24

= (diffrence/original) x 100

= (x-y / y) x 100

Question 25

A 30-60-90 triangle has sides in a ratio of

Answer 25

A 30-60-90 triangle has sides in a ratio of x:x√3:2x, with the 1x side opposite the 30 degree angle.

Question 26

Arc length of a sector

Answer 26

= radius x degrees of central angle / 360