If a = 7 and b = 11, what is the measure of ∠B? (round to the nearest tenth of a degree) A) 32.5° B) 39.2° C) 50.5° D) 57.5°

Respuesta :

Answer:

D) 57.5°

Step-by-step explanation:

As the question is not complete. So, let's suppose it is a right angle triangle then, we can apply Pythagoras theorem to calculate the hypotenuse or the third side.

Pythagoras Theorem = [tex]c^{2}[/tex] = [tex]a^{2} + b^{2}[/tex]

a = 7 and b = 11

[tex]a^{2}[/tex] = 49

[tex]b^{2}[/tex] = 121

Plugging in the values, we will get:

[tex]c^{2}[/tex] = 49 + 121

[tex]c^{2}[/tex] = 170

c = [tex]\sqrt{170}[/tex]

To calculate the unknown angle B, we can use law of sine.

Law of sine = [tex]\frac{a}{sinA}[/tex] = [tex]\frac{b}{sinB}[/tex] = [tex]\frac{c}{sinC}[/tex]

So,

[tex]\frac{c}{sinC}[/tex] = [tex]\frac{b}{sinB}[/tex]

[tex]\frac{\sqrt{170} }{sin90}[/tex] =  [tex]\frac{11}{sinB}[/tex]

Sin90 = 1

sinB = [tex]\frac{11}{\sqrt{170} }[/tex]

B = [tex]sin^{-1}[/tex] ([tex]\frac{11}{\sqrt{170} }[/tex])

B = 57.5°

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