Angles in Circles

What formula would you use to find m<A?

• angle = 1/2 (arc + arc)

• angle = 1/2 (arc - arc)

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

<A is an inscribed angle.
angle = 1/2(arc)

Tags

G.GCI.4

G.GCI.2

What formula would you use to find m<1?

• angle = 1/2 (arc + arc)

• angle = 1/2 (arc - arc)

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

<1 is created from the tangent line, m, and chord AB. 
angle = 1/2(intercepted arc)

Tags

G.GCI.4

G.GCI.2

What formula would you use to find m<x?

• angle = 1/2 (arc + arc)

• angle = 1/2 (arc - arc)

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

<x is created from the secants that cross INSIDE the circle.

angle = 1/2 (arc + arc)

Tags

G.GCI.4

G.GCI.2

What formula would you use to find m<x?

• angle = 1/2 (arc + arc)

• angle = 1/2 (arc - arc)

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

<x is created from the secants that cross OUTSIDE the circle.

angle = 1/2 (larger arc - smaller arc)

Tags

G.GCI.4

G.GCI.2

The sides of circumscribed angles are _________ to the circle.

<B is the circumscribed angle.

• tangent

• secant

• parallel

• perpendicular

Answer explanation

tangent = touches the circle at one point

Tags

G.GCI.4

G.GCI.2

What formula would you use to find m<x?

• angle = 1/2 (arc + arc)

• angle = 1/2 (arc - arc)

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

<x is created from the two tangent lines. It is a circumscribed angle.

circumscribed angle = 180 - central angle

Tags

G.GCI.4

G.GCI.2

A tangent to a circle is ________________________ to the radius drawn to the point of tangency.

• congruent
• perpendicular
• complimentary
• supplementary

Tags

G.GCI.4

G.GCI.2

What formula would you use to find y?

• angle = 1/2 (arc + arc)

• 180 = opposite angle + opposite angle

• angle = 1/2(arc)

• circumscribed angle = 180 - central angle

Answer explanation

180 = opposite angle + opposite angle

Tags

G.GCI.4

G.GCI.2

Identify the angle highlighted in blue.

• Center of the circle

• minor arc

• Central angle

• Inscribed angle

Tags

G.GCI.4

G.GCI.2

Identify the angle highlighted in pink

• center of the circle

• minor arc

• central angle

• inscribed angle

Tags

G.GCI.4

G.GCI.2