find the length XZ in the triangle
-
A.
(sqrt{7m}) -
B.
(sqrt{6m}) -
C.
(sqrt{5m}) -
D.
(sqrt{3m})
Correct Answer: Option A
Explanation
xz2 = xy2 + yx2 – 2(xy) (yz) cos 120o
= 22 + 12 – 2(2) (1) cos 1202
= 4 + 1 – 4x – cos 60 = 5 – 4x – (frac{1}{2})
5 + 2 = 7
xz = (sqrt{7})m