This 45-minute test covers circles for Geometry (G-C.A.1 and G-C.A.2). It has nine questions worth 20 points. Show every calculation, give exact values, and give a reason for each angle you find using a circle theorem.
- Grade: Geometry
- Chapter: Circles: Chords, Arcs and Inscribed Angles
- Common Core: G-C.A.1, G-C.A.2
- Time: 45 minutes
- Total: 20 points (Question 1: 2 pts; Question 2: 2 pts; Question 3: 2 pts; Question 4: 2 pts; Question 5: 3 pts; Question 6: 2 pts; Question 7: 2 pts; Question 8: 3 pts; Question 9: 2 pts)
Question 1: Similar circles (2 points)
Circle \(P\) has radius 6 and circle \(Q\) has radius 15.
- A translation followed by a dilation maps \(P\) onto \(Q\). Find the scale factor. (1 point)
- The circumference of \(P\) is \(12\pi\). Find the circumference of \(Q\). (1 point)
Question 2: Central and inscribed angles (2 points)
In the circle, arc \(AB\) measures \(124^{\circ}\). Point \(O\) is the center and \(C\) is on the circle.
- Find \(m\angle AOB\). (1 point)
- Find \(m\angle ACB\). (1 point)
Question 3: Inscribed angle algebra (2 points)
An inscribed angle measures \((5x+2)^{\circ}\) and intercepts an arc that measures \((12x-12)^{\circ}\). Find \(x\) and the measure of the angle.
Question 4: Triangle in a semicircle (2 points)
Segment \(AB\) is a diameter of length 26. Point \(C\) is on the circle with \(AC=10\).
- Find \(m\angle ACB\). (1 point)
- Find \(BC\). (1 point)
Question 5: Tangent and radius (3 points)
Segment \(PT\) is tangent to the circle with center \(O\) at \(T\). The radius is 9 and \(OP=15\).
- Find \(m\angle OTP\). (1 point)
- Find \(PT\). (1 point)
- If \(m\angle TOP=53^{\circ}\), find \(m\angle OPT\). (1 point)
Question 6: Tangents from a point (2 points)
Tangent segments \(PA\) and \(PB\) touch a circle at \(A\) and \(B\), and \(m\angle APB=64^{\circ}\).
- Find the measure of minor arc \(AB\). (1 point)
- Find the measure of major arc \(AB\). (1 point)
Question 7: Chord and center (2 points)
A chord of length 40 is drawn in a circle with radius 25. Find the distance from the center of the circle to the chord.
Question 8: Inscribed quadrilateral (3 points)
Quadrilateral \(ABCD\) is inscribed in a circle. The angles are \(m\angle A=(3x+15)^{\circ}\), \(m\angle B=(4y+2)^{\circ}\), \(m\angle C=(5x-3)^{\circ}\) and \(m\angle D=(2y+22)^{\circ}\). Find \(x\), \(y\) and the measure of each angle.
Question 9: Skating rink (2 points)
A circular skating rink is 60 feet across. Maya stands at \(A\) and Jamal stands at \(B\), at opposite ends of a diameter. Noah stands at \(N\) on the edge of the rink, 36 feet from Maya.
- Find the measure of the angle formed by Noah’s lines of sight to Maya and Jamal. (1 point)
- How far is Noah from Jamal? (1 point)
See every chapter on the Geometry math page.



