Geometry

Sana

New member
Joined
Jul 27, 2020
Messages
2
Hi all I need help in finding quadrilateral side and angles? Needs to divides two triangles.
 

Attachments

  • Screenshot_20200728_154252.jpg
    Screenshot_20200728_154252.jpg
    64.1 KB · Views: 12
… [Need] to [divide the quadrilateral into] two triangles.
Hi Sana. Here's a hint: Draw a line from A to C. That's one way to begin.

Hopefully, you've already learned how to use the Law of Cosines and Law of Sines. (If not, then please tell us what class you're taking and what you've been studying recently.)

For triangle ACD, you've been given two sides and the angle between them. Use the Law of Cosines, to find side AC.

Side AC is opposite the 65º angle, so you can use the Law of Sines next to find angle ACD.

Once you know angle ACD, you can calculate angle CAD. (Let us know, if you're not sure how.)

After the steps above, there are two more steps to find side BC. Can you see what they are?

If you'd like more help with this exercise, please post your work so far or ask specific questions.

?
 
Am I doing it right?
Thanks for your help.
 

Attachments

  • IMG_20200729_112924.jpg
    IMG_20200729_112924.jpg
    2.1 MB · Views: 7
Am I doing it right? …
Hi Sana. Were you able to continue, after reading Dr. Peterson's reply?

We use Law of Cosines when we know two sides and the angle between them.

Two sides in the diagram are 6 and 15, and the angle between them is 65º. In your work, you'd mistakenly written 140º.

Feel free to let us know, if you need any more help with this exercise.

?
 
Top