In triangle ABC, the length of side AB is 12 cm, the length of side BC is 5 cm, and the length of side CA is 9 cm. Find the measure of angle A using the law of cosines.
Accepted Solution
A:
Answer:Consider two right triangles: 1. ΔABC with vertices A(0,0), B(0,2), C(6,0). Then AB is perpendicular to AC and AB=2 units (vertical leg), AC=6 units (horizontal leg).2. ΔXYZ with vertices X(6,-10), Y(6,0), Z(36,-10). Then XY is perpendicular to XZ and XY=10 units (vrrtical leg), XZ=30 units (horizontal leg).The equation of the line BC is Check whether points Y and Z lie on this line:Y(6,0): - true;Z(36,-10): - true.Answer: the hypotenuses of these two triangles could lie along the same lineStep-by-step explanation: