Circle Equations Review

What is the equation of this circle?

• (x + 3)² + (y - 1)² = 9

• (x - 3)² + (y + 1)² = 9

• (x - 3)² + (y + 1)² = 3

• (x + 3)² + (y - 1)² = 3

What is the circumference of a circle with a diameter of 19.1 ft? 

• 60.00 ft

• 35.17 ft

• 28.67 ft

• 47.17 ft

What is the circumference of a circle with a radius of 21 cm?

• 131.88 cm

• 121.99 cm

• 111.89 cm

• 141.89 cm

What is the circumference of a 12 inch (diameter) pizza?

• 37.68 inches

• 36.68 inches

• 35.68 inches

• 34.68 inches

Find the area of the circle

• 43.96

• 153.86

• 87.82

• 307.72

find the area of the circle below.

• 100 cm

• 225 cm

• 9 cm

• 28.26 cm

Shring's dining room table is round and has a radius of 4.5 feet. What is the tabletop's area?

• 63.585 ft²

• 68.345 ft²

• 64.585 ft²

• 61.345 ft²

The figure shows a circle inside a triangle.  Which equation could be used to find the area of the shaded region?

• = ½bh - 2πr

• = πr² - ½bh

• = ½bh - πd

• = ½bh - πr²

Write the equation at the origin with radius 6.  

• x^2 + y^2 = 6

• x^2 + y^2 = 36

• x  + y = 6

• x + y = 36

Write the equation of a circle with center (7, 0) with radius 3. 

• (x - ^7)^2 + y^2 = 9

• x^2 + (y -7)^2 = 9

• (x - 7)^2 + y^2 = 3

• x^2 + (y -7)^2 = 3