1. Find the length a.
13
11
108°
с
а
B

a = 19.451838 ≈ 20

Step-by-step explanation:

==>Given:

∆ABC with,

<A = 108°

AB = c = 11

AC = b = 13

BC = a = ?

==>Required:

Length of a

==>Solution:

Given 2 sides and a measure of 1 angle, let's find the length of a using the Cosine rule:

a² = b² + c² – 2bc cos(A)

Where a = ?

b = 13

c = 11

A = 108°

Thus,

a² = 13² + 11²- 2(13 × 11) × cos(108)

a² = 169 + 121 - 2(143) × cos(108)

a² = 290 - 286 × (-0.3090)

a² = 290 + 88.374

a² = 378.374

a = √378.374

a = 19.451838 ≈ 20

0.6

39mph

step-by-step explanation:

what is the answer?