Respuesta :

semsee45

Answer:

A = 40°

a = 9.0

b = 10.7

Step-by-step explanation:

The sum of interior angles of a triangle is 180°

⇒ m∠A + 50° + 90° = 180°

⇒ m∠A + 140° = 180°

⇒ m∠A = 180° - 140°

⇒ m∠A = 40°

[tex]\mathsf{\cos(\theta)=\dfrac{adjacent\ side}{hypotenuse}}[/tex]

Given:

  • [tex]\theta[/tex] = 50°
  • side adjacent to the angle = a
  • hypotenuse = 14

[tex]\implies \mathsf{\cos(50)=\dfrac{a}{14}}[/tex]

[tex]\implies \mathsf{a=14\cos(50)}[/tex]

[tex]\implies \mathsf{a=9.0\ (nearest\ tenth)}[/tex]

[tex]\mathsf{\sin(\theta)=\dfrac{opposite\ side}{hypotenuse}}[/tex]

Given:

  • [tex]\theta[/tex] = 50°
  • side opposite to the angle = b
  • hypotenuse = 14

[tex]\implies \mathsf{\sin(50)=\dfrac{b}{14}}[/tex]

[tex]\implies \mathsf{b=14\sin(50)}[/tex]

[tex]\implies \mathsf{b=10.7\ (nearest\ tenth)}[/tex]

Starrysoul100

[tex]\bold{\huge{\underline{ Solution }}}[/tex]

Let consider the given triangle be ABC

Here, It is given in the question that ,

  • [tex]\sf{ {\angle} B = 90° }[/tex]
  • [tex]\sf{ {\angle} C = 50° }[/tex]
  • [tex]\sf{ AC = 14 }[/tex]

Therefore,

By using Angle sum property

  • It states that the sum of all angles of triangles are equal to 180°

That is,

[tex]\bold{\pink{ {\angle} A + {\angle}B + {\angle}C = 180{\degree}}}[/tex]

Subsitute the required values,

[tex]\sf{ {\angle}A + 90{\degree} + 50{\degree}\: =\: 180{\degree} }[/tex]

[tex]\sf{ {\angle}A + 140{\degree}\: = \:180{\degree} }[/tex]

[tex]\sf{ {\angle}A\: = \: 180{\degree} - 140{\degree} }[/tex]

[tex]\sf{ {\angle}A \: =\: 40{\degree} }[/tex]

Thus, The angle A is 40°

Now,

We have to find the side a and b

We know that,

[tex]\bold{\red{ Sin{\theta} \:=\: }}{\bold{\red{\dfrac{Perpendicular }{Hypotenuse }}}}[/tex]

[tex]\bold{\red{ Cos{\theta} \:=\: }}{\bold{\red{\dfrac{ Base }{Hypotenuse }}}}[/tex]

For side A

[tex]\sf{ Sin\: 40 {\degree} \:= \:}{\sf{\dfrac{ a}{ 14 }}}[/tex]

[tex]\sf{ Sin(}{\sf{\dfrac{2{\pi}}{9}}}{\sf{) \:= \:}}{\sf{\dfrac{ a}{14 }}}[/tex]

[tex]\sf{Sin(}{\sf{\dfrac{2{\times} 3.14 }{9}}}{\sf{) \:= \:}}{\sf{\dfrac{ a}{14 }}}[/tex]

[tex]\sf{sin(}{\sf{\dfrac{6.28}{9}}}{\sf{) \:=\: }}{\sf{\dfrac{ a}{14 }}}[/tex]

[tex]\sf{ a \:= \:14 {\times} 0.64}[/tex]

[tex]\sf{ a \: = \:14 {\times} 0.64}[/tex]

[tex]\bold{ a\: =\: 8.96\: \: or \:\:9\:\: (approx) }[/tex]

For Side B

[tex]\sf{ Sin\: 50 {\degree} = }{\sf{\dfrac{ b }{ 14 }}}[/tex]

[tex]\sf{Sin(}{\sf{\dfrac{5{\pi}}{18}}}{\sf{)\: =\: }}{\sf{\dfrac{ b}{14 }}}[/tex]

[tex]\sf{Sin(}{\sf{\dfrac{5{\times} 3.14 }{18}}}{\sf{ ) \: = \:}}{\sf{\dfrac{ b}{14 }}}[/tex]

[tex]\sf{Sin(}{\sf{\dfrac{15.7}{18}}}{\sf{ )\: = \:}}{\sf{\dfrac{ b}{14 }}}[/tex]

[tex]\sf{ b\: = \:14 {\times} 0.76}[/tex]

[tex]\bold{ b\: = \: 10.64\:\: or \:\:10.7\:\: (approx) }[/tex]

Hence, The value of angle A , side a and b is 40° , 9 and 10.7 .

Otras preguntas