Solving for an Unknown Side Length Using the Law of Sines

Published on September 20, 2026

Trigonometry

Calculate the unknown side length x in a triangle using the Law of Sines given two interior angles and one opposite side length.

Question

Answer

Based on the image provided, we have a triangle with the following given information:
  • One side length is .
  • One interior angle is .
  • An exterior angle (or angle formed by a line extending from the base) is .
  • We need to find the length of the side labeled .
Step 1: Find the interior angles of the triangle.
The angle labeled is an exterior angle to the triangle. The interior angle adjacent to it is:
Wait, looking closer at the diagram, the angle is likely the interior angle at that vertex, and the angle is the interior angle at the top vertex. Let’s re-examine the labels.
The angle at the top is . The angle at the bottom right is .
The third angle (top left) is:
Step 2: Identify the sides relative to the angles.
  • Side is opposite the angle.
  • Side is opposite the angle.
Step 3: Use the Law of Sines to solve for .
Step 4: Calculate the final value.
Using and :
Final Answer: