Answer:
D
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Subtract the sum of the 2 given angles from 180
x = 180° - (90 + 35)° = 180° - 125° = 55°
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Since the triangle is right use the cosine ratio to solve for b
cos35° = =
Multiply both sides by 20
20 × cos35° = b, hence
b = 16.38 ( to 2 dec. places )