i need help with these problems if theres anybody that can h

i need help with these problems if theres anybody that can help. i included an image of them.

A weight is supported by cables attached to both ends of a balance beam, as shown in the figure. What angles (alpha, beta) are formed between the beam and the cables? (Round the values to the nearest tenth of a degree). The angle a(alpha) measures__; the angle beta (beta) measures__. Three atoms A, with radius 4.5, B with radius 3, and C with radius 2 units are arranged as shown in the figure. Find the distance between the centers of the atoms A and C. The distance between the centers of atoms A and C is__units.

Solution

1. We have to use law of cosine here

60²=45²+90² - 2*45*90 cos alpha

8100 cos alpha = 6525

cos alpha= 6525/8100

alpha = 36.34 degree

45² = 60²+90²-2*60*90 cos beta

10800 cos beta= 9675

cos beta= 9675/10800

beta=26.38 degree