Back to Central and inscribed angles

Central and Inscribed Angles — Practice Set

Grade 10·22 problems·~30 min·Digital SAT Math·topic·sat-geotrig-circ-inscribed
Work through problems with immediate feedback
A

Recall / Warm-Up

1.

In a circle, the arc intercepted by a central angle measures 84°. What is the measure of the central angle?

2.

A circle has a total arc measure of 360°. A central angle of 120° intercepts minor arc PQPQ. What is the measure of major arc PQPQ?

3.

An angle has its vertex on a circle and its two sides are chords. What type of angle is this?

B

Fluency Practice

Circle with center O, two radii to points A and B forming central angle 130°, minor arc AB highlighted.
1.

Circle OO has center OO. Central angle AOB=130°AOB = 130\degree. What is the measure, in degrees, of minor arc ABAB?

2.

In circle OO, central angle MON=210°MON = 210\degree. What is the measure, in degrees, of minor arc MNMN?

3.

An inscribed angle intercepts an arc of 96°. What is the measure, in degrees, of the inscribed angle?

Circle with inscribed angle ACB = 37° at point C on the circle, intercepted arc AB highlighted below.
4.

Inscribed angle ACBACB measures 37°. What is the measure, in degrees, of intercepted arc ABAB?

5.

Points AA, BB, CC, and DD lie on a circle in that order. Inscribed angle ACB=55°ACB = 55\degree and inscribed angle ADBADB both intercept arc ABAB (the arc not containing CC or DD). What is the measure of angle ADBADB?

C

Varied Practice

1.

In circle OO, central angle POQ=88°POQ = 88\degree. Inscribed angle PRQPRQ also intercepts arc PQPQ. What is the measure of inscribed angle PRQPRQ?

Circle with points X, Y, Z, P in clockwise order. Arc XY = 140° and arc YZ = 80° both shaded yellow to show they form arc XYZ, the intercepted arc. Arc ZX is dashed with a blank. Inscribed angle XPZ at P has a blank.
2.

Points XX, YY, ZZ, and PP lie on a circle in that order. Arc XY=140°XY = 140\degree and arc YZ=80°YZ = 80\degree. Point PP is on arc ZXZX (the remaining arc). Arc $ZX = $   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   degrees. Inscribed angle XPZXPZ, whose vertex is PP and which intercepts arc XYZXYZ (the arc from XX to ZZ going through YY), measures   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   degrees.

arc ZX (degrees):
inscribed angle XPZ (degrees):
3.

In circle OO, the major arc ST=260°ST = 260\degree. Inscribed angle SUTSUT has its vertex UU on the major arc, so it intercepts the minor arc STST. What is the measure of angle SUTSUT?

4.

Point PP is inside circle OO (not on the circle). Two chords pass through PP, forming an angle of 40° at PP. A student claims this is an inscribed angle intercepting an arc of 80°. What error did the student make?

5.

Points AA and BB are the endpoints of a diameter of circle OO. Point CC lies on the circle. What is the measure, in degrees, of inscribed angle ACBACB?

D

Word Problems / Application

1.

A Ferris wheel has its center at point OO. Two spokes extend to seats at points AA and BB on the rim. The angle between the two spokes (central angle AOBAOB) is 72°.

A rider at point CC on the rim of the Ferris wheel sits on the major arc — the longer arc not directly between seats AA and BB. What is the measure, in degrees, of inscribed angle ACBACB?

2.

In a circular garden design, a designer marks points PP, QQ, and RR on a circular path. Arc PQPQ (not containing RR) measures 110°.

The designer wants to place a bench at RR so that the angle PRQPRQ (the view angle from the bench to points PP and QQ) equals 55°. What is the measure of inscribed angle PRQPRQ?

Circle with A and B at upper-left and upper-right, short arc AB at top tinted yellow. C at lower-left and D at lower-right on the major arc. Inscribed angle ADB = 38° at D and inscribed angle ACB = ? at C, both intercepting arc AB.
3.

Points AA, BB, CC, and DD lie on a circle in that order. Inscribed angle ADBADB intercepts arc ABAB (the short arc not containing CC or DD) and measures 38°. Inscribed angle ACBACB also intercepts arc ABAB.

1.

What is the measure, in degrees, of inscribed angle ACBACB?

2.

What is the measure, in degrees, of arc ABAB?

4.

Triangle ABCABC is inscribed in a circle. Side ABAB is a diameter of the circle. The legs of the triangle measure AC=9AC = 9 cm and BC=12BC = 12 cm.

What is the diameter of the circle, in centimeters?

E

Error Analysis

Circle with inscribed angle ACB over diameter AB, showing Jordan's error (treating arc = angle) vs. correct answer of 90°.
1.

Jordan solved the following problem:

"Points A and B are endpoints of a diameter. Point C lies on the circle. Find angle ACB."

Jordan's work:

  1. The diameter = 180°.
  2. Angle ACB = 180° (a straight angle, since AB is a straight line).

What error did Jordan make?

Side-by-side comparison showing Sam using the wrong major arc (230°) vs. the correct minor arc (130°) for inscribed angle PQR.
2.

Sam solved the following problem:

"Inscribed angle PQR intercepts major arc PR = 230°. Find angle PQR."

Sam's work:

  1. Arc PR = 230°.
  2. Angle PQR = ½ × 230° = 115°.

Is Sam's work correct? If not, identify the error.

F

Challenge / Extension

Circle with central angle AOB = 124°, minor arc labeled, major arc highlighted green, point D on minor arc with inscribed angle ADB marked unknown, and step-by-step labels.
1.

In circle OO, central angle AOB=124°AOB = 124\degree. Point CC is on the major arc. Point DD is on the minor arc. Inscribed angle ADBADB intercepts the major arc ABAB. What is the measure, in degrees, of inscribed angle ADBADB?

2.

Quadrilateral ABCDABCD is inscribed in a circle (a cyclic quadrilateral). Angle A=73°A = 73\degree. What is the measure, in degrees, of angle CC?

0 of 22 answered