To use the formula A=12absinC, we need to know the length of side c. Given that we only have the lengths of sides a and b, we need to use the Law of Cosines to find side c.
The Law of Cosines states that:
c² = a² + b² - 2abcosC
Substituting the given values, we have:
c² = 16² + 18² - 2(16)(18)cos(43°)
Solving this equation, we find that:
c² ≈ 324.95
Taking the square root of both sides, we get:
c ≈ 18.03 inches
Now, we can substitute all the values into the formula to find the area:
A = 12absinC
A = 12(16)(18)sin(43°)
Calculating this expression, we find:
A ≈ 231.72 square inches
Therefore, the area of triangle ABC is approximately 231.72 square inches to the nearest square inch.
Use the formula A=12absinC to determine the area of △ABC . What is the area to the nearest square inch if a=16 inches , b=18 inches , and ∠C=43 degrees ?
3 answers
options are:
134 inches2
134 inches squared
196 inches2
196 inches squared
105 inches2
105 inches squared
98 inches2
134 inches2
134 inches squared
196 inches2
196 inches squared
105 inches2
105 inches squared
98 inches2
The correct option is:
196 inches2
196 inches squared
196 inches2
196 inches squared