TEACHER-GUIDE-VERIFIED · TG-V9-071

4. Two truss beams are 8 m and 11 m with included angle 60 degrees. Find the third side.

Verified solution

Solution: c^2=8^2+11^2-2(8)(11)cos60=97; c=sqrt97, about 9.85 m.

Source: Teacher Guide V9 · English V9. Match the numbers and wording in your printed question before using this solution.

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VIDEO HELP · TG-V9-071

Find a Truss Side with the Law of Cosines (TG-V9-071)

Use the included 60° angle: c² = 8² + 11² − 2(8)(11)cos60° = 97 m². Take the positive square root, c ≈ 9.85 m, and check that 3 m < c < 19 m. Use degree mode.

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These pages reproduce verified solution steps for the registered V9 questions. It does not diagnose learning needs or replace instruction from a qualified teacher or tutor.