Answer:
Step-by-step explanation:
You know the lengths of two sides and the angle between them, so use the Law of Cosines to find the third side.
x^2 = 10.5^2+ 5.4^2 -2(10.5)(5.4)cos20°
x ≈ 5.73 units
Answer:
1440°
Step-by-step explanation:
n = number of sides
n-2 x 180
10 - 2 = 8
8 x 180 = 1440°