Question

Find the area of the triangle given a = 13, c = 21, and B = 87 degrees, Round your answer to the nearest tenth, and enter the number only. Note: The figure shown is not drawn to scale.

Answer 1

Answer: 136.3 square units

Work Shown:

area = 0.5*a*c*sin(B)

area = 0.5*13*21*sin(87)

area = 136.312931494

area = 136.3 square units

Notes:

• Make sure your calculator is in degree mode.
• Pay close attention to how angle B is between sides 'a' and 'c'. If this wasn't the case, then the formula above would not work.
• You can use GeoGebra to confirm the answer is correct.