Part 3: Geometry Flashcards Preview

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Flashcards in Part 3: Geometry Deck (39)
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1

What is the equation to calculate the number of degrees in a polygon?

degrees = (n+2)*180, where n is the number of sides.

2

What is the pythagorean theorem?

a^2 + b^2 = c^2, used to determine length of sides in a triangle with one right angle (a right triangle).

3

What is an equilateral triangle?

a triangle where all three sides are the same length (congruent).

4

What is an isosceles triangle?

a triangle where two sides are congruent.

5

What are the ratio of sides in an isosceles right triangle?

a to a√2

6

What are the ratio of sides in an 30-60-90 triangle?

2a to a√3 to a

7

What is the area of a triangle?

(bh)/2, which is base times height divided by 2.

8

What makes for congruent triangles?

All sides are the same. Or one side and two angels are the same. Or one angle and two sides are the same.

9

What makes for similar triangles?

All three angles are the same.

10

What is the area of a quadrilateral?

A = bh

11

What is the area of a trapezoid?

A = 1/2(b1 + b2)h

12

In a circle, what is a chord?

A line segment whose end points touch a circle's circumference.

13

How to determine the length of an arc?

Given the angle of the arc, the length of the arc can be calculated with the following ratio:
arc angle/360 = arc length/circumference

14

What is the area of a circle?

πr^2

15

What is the area of a sector?

Given the angle of the arc of the sector, the area can be calculated using the following ratio:
area of sector/area of circle = sector angle/360

16

What is special about an inscribed triangle and it's angle (or side)?

If one of the sides is the diameter of the circle, then it is a right triangle. If one of the angles of an inscribed triangle is 90 degrees, than one of its sides if the diameter.

17

How is a polygon circumscribe a circle?

If all sides of the polygon are tangential, then it circumscribes the circle.

18

What are concentric circles?

Circles that share the same center point.

19

what is the volume of a rectangular solid?

V = lwh

20

What is the surface area of a rectangular solid?

A = 2(lw + wh + hl)

21

What is the a circular cylinder?

Is a can but where the circles can be slid on their respective planes in any direction.

22

What is a right circular cylinder.

A can.

23

What is an axis in a circular cylinder?

It is the line connecting the center of both circles in a cylinder.

24

What is the volume of a can?

V = πr^2h

25

What is the surface area of a can?

A = 2πr^2 + 2πrh

26

Given two parallel lines and two intersecting lines, one of the angles is 57 degrees and the other is 42. What are x and y.

x is also 57 degrees. y is 180-42, which is 138 degrees.

27

Given an isosceles triangle, and an outside angle of 125 degrees, what are x and y?

y is 125 degrees. x is 180 - 55 - 55 = 70 degrees.

28

Given two inside angles x and y and one outside angle z, what is their relationship to each other?

x + y = z

29

What is the sum of the interior angles inside a decagon?

8*180 = 1440 degrees

30

What is a single angle inside of a regular decagon?

144 degrees