You can add the numbers together so:
12.6
3.1
<u>+ 5.4
</u> 21.1
<u>
</u>Since the sum of the numbers is 21.1, it is greater than 20<u>
</u>
Use the Pythagorean Theorem.
a² + b² = c²
3² + b² = 19²
9 + b² = 361
b² = 352
b = 4√11
Now, solve for the remaining angles by using the trigonometric ratios:
Sine = opposite/hypotenuse
sin(A)= 3/19
sininverse(3/19) = 9.1 = angle A
180-9.1-90 = 80.9 = angle B
