question 4 of 10

the equation for the circle below is $x^2 + y^2 = 81$. what is the length of the circles radius?

a. 81
b. 9
c. 16
d. 4
e. 2
f. -1

Question

question 4 of 10

the equation for the circle below is $x^2 + y^2 = 81$. what is the length of the circles radius?

a. 81
b. 9
c. 16
d. 4
e. 2
f. -1

Accepted Answer

{ "quality": "clear", "question_count": 1, "skills_matched": [ "step_cot", "multiple_choice_formatter", "explain_then_answer", "quick" ], "needs_drawing": true, "concepts_used": [ "Circle Definition", "Circle Radius" ], "new_concepts": [], "current_concepts": [ "Circle Definition", "Circle Radius" ] } ## Identify the standard equation of a circle $$ x^2 + y^2 = r^2 $$ ## Relate the given equation to the standard form $$ r^2 = 81 $$ ## Solve for the radius $$ r = \sqrt{81} = 9 $$

A. 81

B. 9

C. 16

D. 4

E. 2

F. -1

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QUESTION IMAGE

Question

Explanation:

Identify the standard equation of a circle

Relate the given equation to the standard form

Solve for the radius

Answer: