SOLUTION: The length of the base of an isosceles triangle is 30m. The angle opposite the base measures 32° find the perimeter of the triangle to the nearest metre.

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Question 973279: The length of the base of an isosceles triangle is 30m. The angle opposite the base measures 32° find the perimeter of the triangle to the nearest metre.
Answer by Edwin McCravy(20086) About Me  (Show Source):
You can put this solution on YOUR website!
The length of the base of an isosceles triangle is 30m. The angle opposite the
base measures 32° find the perimeter of the triangle to the nearest metre.
We draw the isosceles triangle, letting the two equal sides 
be x meters long each:



Now we draw an altitude, which is also a median, a perpendicular bisector
of the base and the bisector of the vertex angle, which cuts the triangle 
into two congruent right triangles.
Therefore the 32° angle is cut into two 16° angles and the 30m base is cut 
into two 15m segments:



Looking at either of the two congruent right triangles,

sin%28%2216%B0%22%29%22%22=%22%22matrix%281%2C5%2CSIDE%2COPPOSITE%2CTHE%2C%2216%B0%22%2CANGLE%29%2FHYPOTENUSE%29

sin%28%2216%B0%22%29%22%22=%22%2215%2Fx

Multiply both sides by x

x%2Asin%28%2216%B0%22%29%22%22=%22%2215

Divide both sides by sin(16°)

x%22%22=%22%2215%2Fsin%28%2216%B0%22%29

Use calculator:

x%22%22=%22%2215%2F0.2756373558

x%22%22=%22%2254.41932918

So the 3 sides of the triangle are

30m, 54.41932918m, 54.41932918m

So the perimeter is the sum of the three sides,
or

perimeter = 138.83865836m

To the nearest meter is 139m

Edwin