Respuesta :

The length of AB is 31 yd.

Solution:

Given data:

The side opposite to angle A is "a" = 22 yd

The side opposite to angle B is "b" = 26 yd

The side opposite to angle C is "c" = AB

Angle C = 80°

To find the length of AB:

Using cosine formula,

[tex]c^2=a^2+b^2-2ab \cdot \cos C[/tex]

Substitute the given values in the formula, we get

[tex]c^2=22^2+26^2-2(22)(26)\cdot \cos 80^\circ[/tex]

[tex]c^2=484+676-1144\cdot \cos 80^\circ[/tex]

[tex]c^2=1160-1144\cdot (0.1736)[/tex]

[tex]c^2=1160-198.5984[/tex]

[tex]c^2=961.4016[/tex]

Taking square root on both sides, we get

c = 31

AB = 31 yd

The length of AB is 31 yd.