Unit 9 - Circles

Find the center and radius of a circle with the equation x² + y² = 20

• center: (0,0) radius: 2/5

• center: (1,1) radius: 2√7

• center: (0,0) radius: √20

• center: (-1,-1) radius: 10

Write the equation for a circle with center (-1,3) and radius 6.

• (x - 1)² + (y + 3)² = 12

• (x + 1)² + (y - 3)² = 36

• (x - 1)² + (y - 3)² = 6

• (x + 1)² + (y + 3)² = 36

• (x - 1)² + (y - 3)² = 36

Write the equation of the circle.

• (x - 3)² + (y + 1)² = 9

• (x - 3)² + (y + 1)² = 36

• (x + 3)² + (y - 1)² = 36

• (x + 3)² + (y - 1)² = 6

• (x + 3)² + (y - 1)² = 9

Write the equation of a circle with a center of (1, -5) and a radius of √5.

• (x - 1)² + (y + 5)² = 5

• (x + 1)² + (y - 5)² = 5

• (x + 1)² + (y + 5)² = 5

• (x - 1)² + (y - 5)² = 5

Find the center and radius of a circle with equation (x + 4)² + (y + 3)² = 16.

• center: (-4,3), radius: 4

• center: (4,3), radius: 4

• center: (4,-3), radius: 16

• center: (-4,3), radius: 16

• center: (-4,-3), radius: 4

Write the equation of a circle centered at (2,-8) with a diameter of 8.

• (x + 2)² + (y + 8)² = 16

• (x - 2)² + (y - 8)² = 116

• (x + 2)² + (y - 8)² = 64

• (x - 2)² + (y + 8)² = 64

• (x + 2)² + (y + 8)² = 4

Find the equation of a circle with center at (-2, -7) and a radius with endpoint (0,7).

• (x - 2)^2 + (y + 7)^2 = 10

• (x + 2)^2 + (y + 7)^2 = 100

• (x + 2)^2 + (y - 7)^2 = 200

• (x - 2)^2 + (y - 7)^2 = 49

• (x + 2)^2 + (y + 7)^2 = 10

Find the area of the sector, rounding your answer to 1d.p.

• 67.1cm²

• 67.0cm²

• 16.8cm²

• 134.0cm²

Find the area of the sector, rounding your answer to 1d.p.

• 2.1cm²

• 2.0cm²

• 0.5cm²

• 12.6cm²

Find the area of the sector, rounding your answer to 1d.p.

• 209.4cm²

• 209.3cm²

• 104.7cm²

• 104.1cm²