+0  
 
0
211
3
avatar

Find the area of triangle ABC:

 

AB=19, ∠B= 32°.

A line is drawn from C down to AB. We call the point of intersection D. 

AD= 5, ∠ACD=10°.

 

 

I don't know how to set up the equations to find x and y. Help is much appreciate

Guest Nov 30, 2014

Best Answer 

 #1
avatar+26399 
+10

See if this helps:

triangle

(1)  10° + 32° + θ + Φ = 180°

(2) sin(32°)/CD = sin(θ)/12

(3) sin(Φ)/CD = sin(10°)/5

Three equations in three unknowns should enable you to find the angles.

 

Then use the sin rule again to find the lengths of the other sides, AC and BC.

 

Then use Herons formula to find the area:

Area = √[s(s - AB)(s - AC)(s - BC)]  where s = (AB + BC + AC)/2

Alan  Nov 30, 2014
Sort: 

3+0 Answers

 #1
avatar+26399 
+10
Best Answer

See if this helps:

triangle

(1)  10° + 32° + θ + Φ = 180°

(2) sin(32°)/CD = sin(θ)/12

(3) sin(Φ)/CD = sin(10°)/5

Three equations in three unknowns should enable you to find the angles.

 

Then use the sin rule again to find the lengths of the other sides, AC and BC.

 

Then use Herons formula to find the area:

Area = √[s(s - AB)(s - AC)(s - BC)]  where s = (AB + BC + AC)/2

Alan  Nov 30, 2014
 #2
avatar
+5

Thank you so much for this answer! It really helped :)

Guest Nov 30, 2014
 #3
avatar+80913 
0

Very nice, Alan

 

CPhill  Nov 30, 2014

27 Online Users

avatar
avatar
avatar
avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details