# Thread: [Solved] How to find length AB? quadrilateral w/ diag=640, 2 angles given

1. ## [Solved] How to find length AB? quadrilateral w/ diag=640, 2 angles given

1-29 A surveying method to find the distance between two points A and B, between which is an obstacle, is shown in Figure P1-29. The length of CD is 640 feet. As an intermediate step of the surveying method, calculate the lengths of AC and AD.

aaa.jpg

Hello all, can anyone help me figure this out please?

So far I've worked out that AC is 914.67 and AD is 866.85 using sine law, but further than this I'm stumped .

EDIT: Looks like the question didn't ask for the length AB and is unsolvable given the information - it only asks for length AC and AD.

2. Originally Posted by Atom
aaa.jpg
Hello all, can anyone help me figure this out please?

So far I've worked out that AC is 914.67 and AD is 866.85 using sine law, but further than this I'm stumped.

EDIT: Looks like the question didn't ask for the length AB and is unsolvable given the information - it only asks for length AC and AD.
You're right: The problem is described as an intermediate step in finding AB, and you are not given enough information to go beyond what is explicitly asked. (You would probably be given another angle.)

3. Originally Posted by Atom
aaa.jpg
Hello all, can anyone help me figure this out please?

So far I've worked out that AC is 914.67 and AD is 866.85 using sine law, but further than this I'm stumped.

EDIT: Looks like the question didn't ask for the length AB and is unsolvable given the information - it only asks for length AC and AD.
So you have solved the problem!! Watch out for units and significant figures in your answers.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•