Related Rates triangle

  • Thread starter franz32
  • Start date
  • #1
133
0

Main Question or Discussion Point

Hello here's the problem:

Each of the two sides of a triangle are increasing at the rate of 1/2 foot per second, and the included angle is decreasing 2 degrees per second. Find the rate of change of the area when the sides and included angle are respectively 5ft., 8ft., and 60 deg.

Here is my question: How do I find the height of the triangle?
Say my base is 5ft. How do I express it in terms of the given details in the problem?
 

Answers and Replies

  • #2
matt grime
Science Advisor
Homework Helper
9,395
3
Try finding a better formula for the area of a triangle involving the two given sides and the included angle. (Think vector cross products, perhaps.)
 
  • #3
HallsofIvy
Science Advisor
Homework Helper
41,770
911
Area= (1/2) height times base where the "height" is measured perpendicular to the "base". Take one of the given sides as base, and drop a perpendicular to it. The other given side is the hypotenuse of the right triangle formed. The height you need is the "opposite side" of that right triangle.
 

Related Threads for: Related Rates triangle

  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
14
Views
4K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
7
Views
506
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
1
Views
2K
Top