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Question 2:
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a² + b² = c²
x² + 13² = 15²
x² = 15² - 13²
x² = 56
x = √56
x = 2√14 units
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Question 4:
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cos a° = adj/hyp
cos (30) = 12/y
y = 12 ÷ cos(30)
y = 12 ÷ 3√2
y = 4/√2 units
tan a = opp/adj
tan(30) = x/12
x = tan(30) x 12
x = 3√3 x 12
x = 36√3 units