Question

In triangle ABC ,

AB=9cm,BC=6cm and CA=8cm.
AB=9cm,BC=6cm and CA=8cm.Find in degrees to the nearest 0.1°,the size of ∠BAC.
(TR said hint is cos rule)

Answer 1

To find the size of angle BAC in triangle ABC, we can use the Law of Cosines.

Step-by-step explanation:

To find the size of angle BAC, we can use the Law of Cosines. The equation for the Law of Cosines is c^2 = a^2 + b^2 - 2ab*cos(C), where c is the side opposite angle C. In this case, angle BAC is angle C, and AB is side a, BC is side b, and CA is side c. Plugging in the values, we get 8^2 = 9^2 + 6^2 - 2*9*6*cos(BAC). Solving for cos(BAC), we find that cos(BAC) = 0.875. To find the angle, we can take the inverse cosine of 0.875 using a calculator. The angle BAC is approximately 29.8 degrees.