IXL - Determine if a point lies on a circle (Geometry practice)

is a diameter of circle

How long is the radius of circle

Simplify any radicals.

units

Does

(

–

)

lie on circle

yes

ref_doc_title.

Learn with an example

question

This graph shows circle

How long is the radius of circle

Simplify any radicals.

units

Does

(

2.5

8.5

)

lie on circle

yes

key idea

You can use the distance formula to find the length of a line segment on a graph.

(

–

)

(

–

)

solution

The radius of circle

is 8 units.

Every point on circle

is 8 units from point

So, if point

lies on circle

then the length of

should be 8.

Use the distance formula to find

is at

(

2.5

8.5

)

and

is at

(

–

)

(

–

2.5

)

(

–

8.5

)

(

–

3.5

)

(

–

7.5

)

12.25

56.25

68.5

Since

is not the same length as the radius of circle

point

does not lie on circle

Looking for more? Try these:

Lesson: Distance formula

$Confetti$

Excellent!

Now entering the Challenge Zone—are you ready?

Questions
answeredQuestions

Time
elapsedTime

hr	min	sec
00	00	06

SmartScore
out of 100
IXL's SmartScore is a dynamic measure of progress towards mastery, rather than a percentage grade. It tracks your skill level as you tackle progressively more difficult questions. Consistently answer questions correctly to reach excellence (90), or conquer the Challenge Zone to achieve mastery (100)! Learn more

Teacher tools

Work it out

Not feeling ready yet? These can help:

B.13Distance formula

Y.2Find the radius or diameter of a circle

EE.8Simplify radical expressions: mixed review

Lesson: Distance formula

Excellent! You got that right!

Jumping to level 1 of 1

Excellent!