What is the area of a circle with a radius of 7 cm? (Use 3.14 and round to the nearest tenth.)
1 answer:
You might be interested in
Answer:
5.545
Step-by-step explanation:
This problem can be easily solved by using the law of cosines, which relates the lengths of the sides of a triangle to the cosine of one of its angles.
in this case, the formula can be applied in the following way
a^2 = b^2 + c^2 - 2*b*c*cos(α)
Where
a,b,c are each of the sides of the triangle,
α is the angle between sides b and c
(See attached picture)
If we use the formula we get
a^2 = (9)^2 + (6)^2 - 2*(9)(6)*cos(37°)
a^2 = 81 + 36 - 86.2526
a^2 = 30.747
a = sqrt(30.747)
a = 5.545
