Answer:
28
Step-by-step explanation:
give brinilist
Cosine law
a^2 = b^2 + c^2 - 2(b)(c)cosA
a^2 = 2^2 + 4^2 - 2(2)(4)cos78
a = 4.08
a = 4.1
Answer:
KL = 9
Step-by-step explanation:
(7 + x - 1)(x - 1) = 12²
(x + 6)(x - 1) = 144
x² -x + 6x - 6 = 144
reduce:
x² + 5x -150 = 0
(x + 15)(x - 10) = 0
x = -15, x = 10
KL = 10 - 1 = 9
