Circle Vocabulary
What is an isosceles triangle?
Measures double the measure of an inscribed angle ending at the same points.
What is a central angle?
A line segment with both endpoints in the circumference of a circle.
What is a chord?
A line that touches a circle at only one point on the circumference.
What is a tangent line?
A line that cuts another line into two equal halves.
What is a bisector?
Two angles that are equal if they are subtended by the same arc.
What are inscribed angles?
This bisects a chord.
What is a radius perpendicular to the chord?
The point on a tangent line that touches the circumference of a circle.
What is the point of tangency?
An angle formed by two radii.
What is a central angle?
Inscribed angles in a triangle that cross the diameter measure this.
What is 90 degrees?
In this circle with centre O, AC=36m and OB=12m. What is the length of the diameter?
43.27 m
In this circle with centre O, CD is tangent to the circle at B. What is the measure of <BOA?
72 degrees
An angle formed by two chords that share one common endpoint.
What is an inscribed angle?
In this circle, what is the measure of <ADC?
72 degrees.
In this circle with centre O, what is the length of chord CD?
18.65
In this circle with centre O, what is the length of CB?
11.07
A piece of the circumference of the circle.
What is an arc?
In this circle with centre O, OB=7cm and CA=10cm. Find AB.
9.8 cm
In this circle with centre O, CE=5 and DO=3. What is the length of AB?
6
In this circle with centre O, AC is tangent to the circle at B. Determine the measure of <EOB.
56 degrees.