Circles

Question 1

In a circle, when a triangle is formed by connecting the endpoints of two radii then the triangle is…

Answer 1

Isosceles!

Question 2

In every circle the ratio of the circumference to the diameter is..

Answer 2

exactly the same and is denoted by the symbol π (otherwise known as the Greek letter “pi”)

Question 3

“Pi” or π =

Answer 3

circumference/diameter = (c/d)

Question 4

Circumference =

Answer 4

πd or 2πr

Question 5

The value of π is approximately…

Answer 5

3.14

Question 6

An arc consists of…

Answer 6

two points on a circle and all the points between them. On the GRE, arc AB always refers to the smaller arc joining A and B.

Question 7

If the vertex of an angles is at the center of a circle it is called a…

Answer 7

central angle

Question 8

The degree measure of an arc =

Answer 8

the degree measure of the central angle that intercepts it.

Question 9

The formula for the area of a circle when r is known…

Answer 9

A = πr^2

Question 10

If an arc measures x degrees, the equation for the length of the arc is ?

Answer 10

(x/360)*(2πr) = length of arc

Question 11

If d is the diameter and the radius of a circle is half the diameter…

Answer 11

d = 2r

Question 12

Circumference =

Answer 12

3πr

Question 13

The equation to calculate the length of an arc is?

Answer 13

(x degrees/360) * 2πr

Question 14

The equation used to find the area of an arc is?

Answer 14

( x degrees / 360) * π r ^ 2

Question 15

C =

Answer 15

2πr

Question 16

A =

Answer 16

πr^2

Question 17

In terms of Circumference and diameter π =

Answer 17

C/d

Question 18

A circle =

Answer 18

πr^2

Question 19

The area of the sector formed by arc and 2 radii is?

Answer 19

x/360*(πr^2)