Inscribed angles and inscribed quadrilaterals
Grade 10 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.
Bo cuts a triangle out of a round pizza, corners on the crust. △CDF is inscribed in circle O, with arc CD = 100° and arc DF = 120°. What is ∠CDF, in degrees?
Esme paints a triangle on a round plate, corners on the rim. △CDF is inscribed in circle O, with arc CD = 60° and arc DF = 70°. What is ∠CDF, in degrees?
Circle sketch, not to scale: center O; △CDF on the circle; arc CD = 60° and arc DF = 70° (neither holds the third corner). Circle sketch, not to scale: center O; △CDF on the circle; arc CD = 60° and arc DF = 70° (neither holds the third corner). O C D F 60° 70° Not to scale Kira joins three points on a clock face. △CDF is inscribed in circle O, with arc CD = 110° and arc DF = 90°. What is ∠CDF, in degrees?
Circle sketch, not to scale: center O; △CDF on the circle; arc CD = 110° and arc DF = 90° (neither holds the third corner). Circle sketch, not to scale: center O; △CDF on the circle; arc CD = 110° and arc DF = 90° (neither holds the third corner). O C D F 110° 90° Not to scale Luz designs a four-sided window in a round frame. Quadrilateral CDFG is inscribed in circle O, with arcs CD = 80°, DF = 90° and FG = 100°. What is ∠C, in degrees?
Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 80°, arc DF = 90°, arc FG = 100°; ∠C = ∠GCD. Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 80°, arc DF = 90°, arc FG = 100°; ∠C = ∠GCD. ∠C = ∠GCD 80° 90° 100° O C D F G Not to scale. Milo sews a four-sided patch on a round rug. Quadrilateral CDFG is inscribed in circle O, with arcs CD = 70°, DF = 110° and FG = 60°. What is ∠C, in degrees?
Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 70°, arc DF = 110°, arc FG = 60°; ∠C = ∠GCD. Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 70°, arc DF = 110°, arc FG = 60°; ∠C = ∠GCD. 70° 110° 60° O C D F G Not to scale. Noah joins four points on a big clock face. Quadrilateral CDFG is inscribed in circle O, with arcs CD = 95°, DF = 75° and FG = 125°. What is ∠C, in degrees?
Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 95°, arc DF = 75°, arc FG = 125°; ∠C = ∠GCD. Circle sketch, not to scale: center O; C, D, F, G in order on the circle; arc CD = 95°, arc DF = 75°, arc FG = 125°; ∠C = ∠GCD. arc CD = 95° arc DF = 75° arc FG = 125° ∠C = ∠GCD O C D F G Not to scale. Ren cuts a pizza through the middle. CF is a diameter of circle O, D is on the circle, ∠DCF = (2x + 6)° and ∠DFC = (x + 9)°. What is ∠DCF?
Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (2x + 6)°, ∠DFC = (x + 9)°. Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (2x + 6)°, ∠DFC = (x + 9)°. O C F D (2x + 6)° (x + 9)° Not to scale Tala draws a triangle on a plate. CF is a diameter of circle O, D is on the circle, ∠DCF = (3x − 4)° and ∠DFC = (2x + 9)°. What is ∠DCF?
Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (3x − 4)°, ∠DFC = (2x + 9)°. Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (3x − 4)°, ∠DFC = (2x + 9)°. O C F D (3x − 4)° (2x + 9)° Not to scale Zee draws a triangle on a clock face. CF is a diameter of circle O, D is on the circle, ∠DCF = (x + 12)° and ∠DFC = (4x − 2)°. What is ∠DCF?
Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (x + 12)°, ∠DFC = (4x − 2)°. Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (x + 12)°, ∠DFC = (4x − 2)°. O C F D (x + 12)° (4x − 2)° Not to scale Ari paints a triangle on a drum top. CF is a diameter of circle O, D is on the circle, ∠DCF = (5x + 3)° and ∠DFC = (x + 9)°. What is ∠DCF?
Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (5x + 3)°, ∠DFC = (x + 9)°. Circle sketch, not to scale: center O; diameter CF; D on the circle; ∠DCF = (5x + 3)°, ∠DFC = (x + 9)°. O C F D (5x + 3)° (x + 9)° Not to scale