Math 7-8
Cross Products
A cross product of two fractions is the product of the numerator of one fraction with the denominator of the other fraction.
Reduction
A dilation with a scale factor between 0 and 1.
Enlargement
A dilation with a scale factor greater than 1.
Scale Drawings
A drawing that is similar but either larger or smaller than the actual object.
Scale
A proportion between two sets of dimensions used in developing accurate, larger or smaller prototypes, or models of design ideas.
dilation
A transformation that changes the size of an object, but not the shape.
Cosine
Adj./Hyp.
Scale Model
An enlarged or reduced representation of an object that is usually intended for study purposes.
Proportions
An equation stating that two ratios are equal.
Inverse Cosine
An inverse trigonometric ratio, abbreviated as cosˉ¹. For acute angle A, if cosA=z, then cosˉ¹z=m<A
Inverse Sine
An inverse trigonometric ratio, abbreviated as sinˉ¹. For acute angle A, if sinA=y, then sinˉ¹y=m<A
Inverse Tangent
An inverse trigonometric ratio, abbreviated as tanˉ¹. For an acute angle A, if tanA=x, then tanˉ¹=m<A
geometric mean
Either of the two means of a proportion in which the means are equal. Also called the mean proportional.
Extremes
In a proportion, the numerator of the first fraction and the denominator of the second fraction
Means
In a/b=c/d, the numbers b and c.
Tangent
Opp./Adj.
Sine
Opp/Hyp.
Similar Polygons
Polygons that have the same shape, but not necessarily the same size. Corresponding sides of similar polygons are proportional.
Scale Factor of a Dilation
The ratio of a side length of the image(new) to the corresponding side length of the original figure(old).
Extended Ratios
These can be used to compare three or more quantities.
Similarity Transformation
When a figure and its transformation image are similar.
ratio
a comparison of two quantities using division.
Mid-segment of a Triangle
a line segment that connects the midpoints of two sides of a triangle
Trigonometric Ratio
a ratio of two sides of a right triangle.
Pythagorean Triple
a set of three positive integers that work in the pythagorean theorem
Center of Dilation
in a dilation, the fixed point about which the figure is enlarged or reduced
Trigonometry
the mathematics of triangles and trigonometric functions.
Scale Factor
the ratio of the lengths of two corresponding sides of two similar polygons.
