Answer:
option 4
Step-by-step explanation:
using the sine/ cosine ratios in the right triangle and the exact values
cos30° = , sin30° = , then
cos30° = = = ( cross- multiply )
2x = 20 × = 20 × 3 = 60 ( divide both sides by 2 )
x = 30
and
sin30° = = = ( cross- multiply )
2y = 20 ( divide both sides by 2 )
y = 10
the answer is a period
55
45, 45, 90 is one of the most common angles which mostly makes the base of the sides to be 7,7,
6,12,24,30,36,42,
11,22,33,44,55,66
14,28,42,56,70,84