anonymous050
anonymous050 anonymous050
  • 03-08-2019
  • Mathematics
contestada

In △ABC,a=14, b=17, and c=22. Find m∠A.

Respuesta :

gmany
gmany gmany
  • 03-08-2019

Answer:

[tex]\large\boxed{m\angle A\approx39^o}[/tex]

Step-by-step explanation:

Use the cosine law:

[tex]a^2=b^2+c^2-2bc\cos A[/tex]

We have:

[tex]a=14,\ b=17,\ c=22[/tex]

Substitute:

[tex]14^2=17^2+22^2-2(17)(22)\cos A\\\\196=289+484-748\cos A\\\\196=773-748\cos A\qquad\text{subtract 773 from both sides}\\\\-577=-748\cos A\qquad\text{divide both sides by (-748)}\\\\\cos A=\dfrac{577}{748}\\\\\cos A\approx0.7714\to m\angle A\approx39^o[/tex]

Answer Link

Otras preguntas

PLEASE HELP. (Find the area of park)
solve .1-cot⁴o / sin⁴o = 1+2 cot²o​
Handwritten solution required
***Urgent*** Find the equation of the tangent line to the graph of y = 3^(x − 2) at x = 1. Give your answer in slope-intercept form. Show all your work.
Which are the reflections of shape Y?
metal element and non metallic element ​
What character trait did Nya have that helped her get through her long walks to water
You borrow 600$ to buy a violin.simple annual interest rate is 15$ you pay off the loan after 2 years of equal monthly payment. How much is each payment
8 friends went out to lunch and the bill was $71.21 including tax and gratuity. One of them ordered only a soda and needed to pay $1.56 the other 7 friends orde
Fatimah spent 1/4 of her money on 8 cookies and 2 muffins. A muffin cost three times as much as a cookie. She bought some more cookies with 2/7 of her remaining