# third quarter vocab

## 27 terms

### diagonal

in a polygon, a segment that connects nonconsecutive vertices of the polygon

### isosceles trapezoid

a trapezoid in which the legs are congruent, both pairs of base angles and congruent, and the diagonals are congruent

### kite

a quadrilateral with exactly two distinct adjacent congruent sides

### parallelogram

a quarilateral with parallel opposite sides. Any side of a parallelogram may be called a base

### rectangle

a quadrilateral with four right angles

### rhombus

a quadrilateral with all four sides congruent

### square

a quadrilateral with four right angles and four congruent sides

### trapezoid

a quadrilateral with exactly one pair of parallel sides. The parallel sides of this are called bases. The nonparallel sides are called legs. The pairs of angles with their vertices at the endpoints of the same base are called base angles.

### median

in a triangle, a line segment with endpoints that are a vertex of a triangle and the midpoint of the side opposite the vertex and in a trapezoid, the segment that joins the midpoints of the legs

### cross products

in the proportion a/b=c/d, where b does not equal 0, the _____________ are ad and bc. The proportion is true if and only if they are equal.

### extremes

in a/b=c/d, the numbers a and d

### means

in a/b=c/d, the numbers b and c

### midsegment

a segment with endpoints that are the midpoints of two sides of a triangle

### proportion

an equation of the form a/b=c/d that states that two ratios are equal

### ratio

a comparison of two quantities using division

### scale factor

the ratio of the lengths of two corresponding sides of two similar polygons or two similar solids

### similar polygons

polygons have the same shape but may bye different in size

### angle of depression

the angle between the line of sight and the horizontal when an observer looks downward

### angle of elevation

the angle between the line of sight and the horizontal when an observer looks upward

### cosine

for an acute angle of a right triangle, the ratio of the measure of the leg adjacent to the acute angle to the measure of the hypotenuse

### geometric mean

for any positive numbers a and b, the positive number x such that a/x=x/b

### Pythagorean triple

a group of three whole numbers that satisfies the equation a2+b2=c2 where c is the greatest number

### sine

for an acute angle of a right triangle, the ratio of the measure of the leg opposite the acute angle to the measure of the hypotenuse

### solving a triangle

finding the measure of all of the angles and sides of a triangle

### tangent

for an acute angle of a right triangle, the ratio of the measure of the leg opposite the acute angle to the measure of the leg adjacent to the acute angle

### trigonometric ratio

a ratio of the lengths of sides of a right triangle

### trigonometry

the study of the properties of triangles and trigonometric functions and their applications

Create Set