Showing posts with label solve triangles. Show all posts
Showing posts with label solve triangles. Show all posts

Wednesday, December 31, 2014

In OPQ, o = 870 inches, P = 80 degrees, and Q = 9 degrees. Find the length of p to the nearest 10th of an inch.

We'll denote the measure of angle X as
m%28X%29
In any triangle the sum of the angles is 180 degrees, so
m%28P%29%2Bm%28Q%29%2Bm%28O%29=180
so we know
m%28O%29=180-%28m%28P%29%2Bm%28Q%29%29=180-89=91
Now using the Law of Sines we write:

%0D%0Ap%2Fsin%2880%29=%28870%29%2F%28sin%2891%29%29%0D%0A

which leads to
p=856.9

Friday, April 4, 2014

solve triangle XYZ where angle X=40, x=12 and y=6

Law of Sines: sinY=(6/12)sin40
sinY=0.3214
Y=arcsine(0.3214)
Y=18.747

Since all angles must add to 180 degrees:
Z=180-40-18.747=121.25
now we find z...
z=12(sin121.25/sin40)=15.96 

A triangle has 45, 105 and 30 degree angles the smallest side is 8. What is the perimeter?

We can use the Law of Sines: 

8%2Fsin%2830%29=b%2Fsin%2845%29 
b=8sqrt%282%29 
8%2Fsin%2830%29=c%2Fsin%28105%29 
c=8sqrt%28sqrt%283%29%2B2%29 


P=8%281%2Bsqrt%282%29%2Bsqrt%28sqrt%283%29%2B2%29%29 

rounded...P=34.77

Tuesday, April 30, 2013

Find the remaining angles and sides of each triangle if it (they) exists. If no triangle exists, say “no triangle” A=10(degrees), B=40 (degrees), side c=2

A=10(degrees), B=40 (degrees), side c=2




Solution:

A=10deg, B=40deg, c=2 

First let's find the missing angle: 


C=180-%2810%2B40%29 


We can solve this triangle by using the Law of Sines. 


a%2FsinA=c%2FsinC
a%2Fsin10=2%2Fsin130
a=%282%2Asin10%29%2FSin130 


which is approximately 0.453 
Similarly...


b=%282%2Asin40%29%2FSin130 


which is approximately 1.678

Thursday, April 18, 2013