Math Problem Statement

In a circle, F, AB, BC, CD, BD, and AC are chords. Use the diagram to solve: 1) Which inscribed angles are congruent? 2) If m∠CBD = 54°, what is the measure of arc CD? 3) If arc AB = 96°, what is the measure of ∠ACB? 4) If m∠ABD = 5x + 3 and m∠DCA = 4x + 10, find: (a) value of x, (b) m∠ABD, (c) m∠DCA, (d) arc AD. 5) If m∠BDC = 6x - 4 and arc BC = 10x + 2, find: (a) value of x, (b) m∠BDC, (c) arc BC, (d) ∠BAC.

Solution

Let me help you analyze the worksheet questions based on the image. Here's a breakdown of the problems and their solutions:

1. Which inscribed angles are congruent?

Solution: Inscribed angles subtended by the same arc in a circle are congruent. Based on the diagram:

  • BCD\angle BCD and BAD\angle BAD both subtend arc BDBD, so they are congruent.

Thus, the congruent angles are BCD\angle BCD and BAD\angle BAD.


2. If mCBD=54m \angle CBD = 54^\circ, what is the measure of CD\overset{\frown}{CD}?

Solution: In a circle, the inscribed angle is half the measure of the intercepted arc. Thus: mCD=2×mCBD=2×54=108m \overset{\frown}{CD} = 2 \times m \angle CBD = 2 \times 54^\circ = 108^\circ


3. If mAB=96m \overset{\frown}{AB} = 96^\circ, what is the measure of ACB\angle ACB?

Solution: The measure of an inscribed angle is half of the arc it intercepts. Since ACB\angle ACB intercepts arc ABAB, we have: mACB=12×mAB=12×96=48m \angle ACB = \frac{1}{2} \times m \overset{\frown}{AB} = \frac{1}{2} \times 96^\circ = 48^\circ


4. If mABD=5x+3m \angle ABD = 5x + 3 and mDCA=4x+10m \angle DCA = 4x + 10, find:

a. The value of xx

Since both angles subtend the same arc ADAD, they must be equal. Therefore, we set the expressions for the angles equal to each other: 5x+3=4x+105x + 3 = 4x + 10 Solving for xx: x=7x = 7

b. mABDm \angle ABD

Substitute x=7x = 7 into 5x+35x + 3: mABD=5(7)+3=35+3=38m \angle ABD = 5(7) + 3 = 35 + 3 = 38^\circ

c. mDCAm \angle DCA

Since mABD=mDCAm \angle ABD = m \angle DCA (as they subtend the same arc), mDCA=38m \angle DCA = 38^\circ.

d. mADm \overset{\frown}{AD}

Since both angles subtend arc ADAD, we know: mAD=2×mABD=2×38=76m \overset{\frown}{AD} = 2 \times m \angle ABD = 2 \times 38^\circ = 76^\circ


5. If mBDC=6x4m \angle BDC = 6x - 4 and mBC=10x+2m \overset{\frown}{BC} = 10x + 2, find:

a. The value of xx

The angle BDC\angle BDC is an inscribed angle subtending arc BCBC, so: mBC=2×mBDCm \overset{\frown}{BC} = 2 \times m \angle BDC Substitute the expressions: 10x+2=2×(6x4)10x + 2 = 2 \times (6x - 4) 10x+2=12x810x + 2 = 12x - 8 Solving for xx: 2x=10x=52x = 10 \quad \Rightarrow \quad x = 5

b. mBDCm \angle BDC

Substitute x=5x = 5 into 6x46x - 4: mBDC=6(5)4=304=26m \angle BDC = 6(5) - 4 = 30 - 4 = 26^\circ

c. mBCm \overset{\frown}{BC}

Substitute x=5x = 5 into 10x+210x + 2: mBC=10(5)+2=50+2=52m \overset{\frown}{BC} = 10(5) + 2 = 50 + 2 = 52^\circ

d. mBACm \angle BAC

Since mBACm \angle BAC subtends arc BCBC, we can use the inscribed angle rule: mBAC=12×mBC=12×52=26m \angle BAC = \frac{1}{2} \times m \overset{\frown}{BC} = \frac{1}{2} \times 52^\circ = 26^\circ


Would you like more details or explanations on any of these solutions?

Here are 5 additional questions for deeper understanding:

  1. Why are the inscribed angles subtending the same arc always congruent?
  2. How do we determine the measure of an arc from an inscribed angle?
  3. What is the relationship between the arc and its central angle in a circle?
  4. Can two inscribed angles subtend different arcs yet still be congruent?
  5. How does the circle theorem apply when calculating the measure of an intercepted arc?

Tip: Always remember that an inscribed angle is half the measure of the intercepted arc.

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Math Problem Analysis

Mathematical Concepts

Geometry
Circles
Inscribed Angles
Arcs
Equations

Formulas

m(Inscribed Angle) = 1/2 × m(Intercepted Arc)
If two angles subtend the same arc, they are congruent.

Theorems

Inscribed Angle Theorem
Congruent Angles Subtending the Same Arc

Suitable Grade Level

Grades 9-11