The value of x is 7.5. It can be evaluated as follows:
Given that:
[tex]a + b = 15[/tex]
y is perpendicular for both the composing right angled triangles.
The two of its angles are 60 degrees and 30 degrees respectively.
Calculations:
By using cotangent trigonometric ratios, we have:
[tex]cot(60) = \dfrac{a}{y}\\\\\dfrac{1}{\sqrt{3}} = \dfrac{a}{y}\\\\cot(30) = \dfrac{b}{y}\\\\\sqrt{3} = \dfrac{b}{y}\\[/tex]
Adding both the values, we get:
[tex]\sqrt{3} + \dfrac{1}{\sqrt{3}} = \dfrac{a+b}{y} = \dfrac{15}{y}\\\\\dfrac{4}{\sqrt{3}} = \dfrac{15}{y}\\\\y = \dfrac{15 \times \sqrt{3}}{4}\\[/tex]
And thus we have: [tex]a = \dfrac{y}{\sqrt{3}} = \dfrac{15}{4}[/tex]
From Pythagoras Theorem we have:
[tex]x^2 = y^2 + a^2\\\\x^2 = \dfrac{225 \times 3}{16} + \dfrac{225}{16} = \dfrac{225}{4}\\x = \sqrt{\dfrac{225}{4}} = \dfrac{15}{2} = 7.5[/tex]
Thus, the value of x is 7.5
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