Math Problem Statement

Below is a circle with centre O. A, B, and C are points on the circumference. A tangent to the circle passes through point A. Given that angle BAC is 23° and angle ACB is 71°, find the size of angle x. You must show your workings.

Solution

To solve the given problem, let's carefully apply the circle theorems and properties.

Key Information:

  1. Circle Properties:

    • The angle between the tangent and a chord at the point of contact is equal to the angle in the alternate segment (alternate segment theorem).
    • The sum of the angles in a triangle is 180180^\circ.
  2. Given Values:

    • BAC=23\angle BAC = 23^\circ,
    • ACB=71\angle ACB = 71^\circ.

We are tasked to find the value of xx^\circ.


Steps to Solve:

  1. Use the Alternate Segment Theorem:

    • The angle between the tangent and the chord (x\angle x) is equal to the angle in the alternate segment, which is ACB=71\angle ACB = 71^\circ.

    Therefore: x=71x = 71^\circ


Conclusion:

The value of xx^\circ is: 71\boxed{71^\circ}

Let me know if you'd like further clarifications or detailed explanations about the theorems used!


Related Questions:

  1. How does the alternate segment theorem work in circles?
  2. Can the value of xx change if the positions of AA, BB, or CC were altered?
  3. What other angle properties of circles could be applied in similar problems?
  4. How can tangents to a circle help solve geometric problems?
  5. Could this problem be extended with the radius of the circle?

Tip: Always identify known relationships, such as the tangent and alternate segment theorem, when solving circle geometry problems.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Circle Geometry
Angles
Alternate Segment Theorem

Formulas

Sum of angles in a triangle = 180°

Theorems

Alternate Segment Theorem

Suitable Grade Level

Grades 9-11