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43 Cards in this Set
- Front
- Back
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measure of an exterior angle of a trangle is equal to...
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the sum of the measures of two opposite interior angles
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in any triangle...
the longest side is opposite... the shortest side is opposite... sides with same length are opposite... |
-largest angle
-smallest angle angles with the same measure |
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in a 45-45-90 right triangle,
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sides are x, x, and x√2
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The diagonal of a square divides the square into...
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2 isoceles triangles
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an altitude of an equilateral triangle divides it into
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two 30-60-90 triangles
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in a 30-60-90 triangle, the sides are...
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x, x√3, and 2x where the hypotenuse if 2x
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the sume of the lnegths of any two sides of a triangle is...
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grater than the length of the third side
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the difference of the lengths of any two sides of a triangle is...
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less than the length of the third side
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in any quadrilateral, the sum of the measures of the four angles...
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360°
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the diagonals of a rectangle...
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have the same length
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each diagonal of a square divides the square into two...
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45-45-90 triangles
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area of a parallelogram equals
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A = bh
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circumference of a circle =
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C = ∏d or 2∏r
∏ = pi |
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the degree measure of an arc...
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equals the degree measure of the central angle that intercepts it
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area of a circle =
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∏r²
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a line tangent to a circle is perpendicular to...
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the radius drawn to the point of contact
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volume of a rectangular solid =
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V = lwh
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surface area of a rectangular solid is...
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A = 6e²
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volume of a cylinder is...
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V = ∏r²h
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What are the rules governing exponents (addition, subtr etc)
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bⁿb² = b^n+2
bm/bn = b^(m-n) (b^m)^n = b^mn (b^m)(c^n) = (bc)^m where ^ = raised to a power |
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to compare 2 decimals...
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whichever number has a greater number to the left of the decimal point is greater; add zeros to make the number of digits equal to the right of the decimal; compare numbers to the right of the decimal point - so for 1.83 and 1.823, you're comparing 1.830 which is > 1.823
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when comparing fractions...
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always use your calculator!
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to divide a number by a fraction...
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multiply by the reciprocal
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to convert a percent to a decimal...
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drop the % and move the decimal point 2 places to the left, adding zeroes if necessary
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to convert a percent to a fraction...
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drop the %, write the number over 100 and reduce
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for any problem involving percents...
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try to use the number 100
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percent increase =
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actual increase / original amount
x 100% |
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200% of a number is...
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2-times that number
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if a set of objects is divided into a ratio of a:b, then...
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the first group contains a / a+b of the objects and the second group has b /(a+b) of the objects
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if two numbers are in a ratio of a:b, then for some number x,
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the first number is ax and the second number is bx
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solve proportion problems by...
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cross-multiplying
if a/b = c/d, the ad = bc |
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set up rate problems like...
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ratio problems
use cross multiplying |
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rate problems are examples of
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direct variation. One variable varies directly with second if they are directly proportional
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average of a set of n numbers =
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sum of n numbers / n
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a polynomial
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= monomial or the sum of two or more monomials (each monomial in a polynomial is called a term
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what are like terms in a polynomial?
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ones that have the same variables and exponents - like
5a²b and -3a²b |
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in a polynomial, you can only combine...
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like terms
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what are the 3 most important binomial products on the PSAT?
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(x-y)(x+y)=x²- y²
(x-y)²= x²-2xy+y² (x+y)²= x²+2xy+y² |
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Steps for solving equations
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get rid of parentheses, combine like terms, put variables on one side, put a plain number on the opposite of the variable, solve for x
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to solve a system of equations... (2 things)
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1. add or subtract them or
2. if there are more than 2 equations, add them. |
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rate x time =
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distance
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years ago means you need to...
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subtract
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what are the angle relationships with a transversal?
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all 4 acute angles are equal and all 4 obtuse angles are equal
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