Answer:
32.7°
Step-by-step explanation:
Use the formula for law of cosines, for this question we need so solve for angle B, so use...
b² = a² + c² - 2(a)(c)Cos B
We are given a, b, and c, so plug them in...
55² = 90² + 50² - 2(90)(50)Cos B
Now simplify...
3,025 = 8100 + 2500 - (9000)Cos B
-7,575 = -(9000)Cos B (subtract 8100 and 2500 from both sides)
0.841666667 = Cos B (divide both sides by -9000)
Cos^(-1) 0.841666667 = B (use cosine inverse function on calculator)
(-1,1.5) because you add both ys and both xs then divide by two to find the middle
Answer:
144 degrees
Step-by-step explanation:
We can use the formula (n-2)(180), where n = number of sides, to find the sum of all the interior angles in the decagon. Since a decagon has 10 sides:
(n-2)(180) = ?
(10-2)(180) = ?
(8)(180) = 1440.
Now, to find one interior angle in the decagon, divide 1440 by the number sides in our polygon (10).
1,440/10 = 144
= <u>144 degrees</u>
