My Math Forum  

Go Back   My Math Forum > High School Math Forum > Trigonometry

Trigonometry Trigonometry Math Forum


Reply
 
LinkBack Thread Tools Display Modes
October 4th, 2017, 10:46 AM   #1
Newbie
 
Joined: Oct 2017
From: Houston

Posts: 1
Thanks: 0

Missing Side Calculation


I'm trying to find the lengths of A and B in the photo. Any help?
klbevan is offline  
 
October 5th, 2017, 07:42 AM   #2
Global Moderator
 
Joined: Dec 2006

Posts: 18,155
Thanks: 1422

As (1086' + A)/A = 13744/13312, A = 1086' × 13312/(13744 - 13312) = 301184'/9.
skipjack is offline  
October 5th, 2017, 08:01 AM   #3
Senior Member
 
Joined: Apr 2014
From: Glasgow

Posts: 2,074
Thanks: 695

Math Focus: Physics, mathematical modelling, numerical and computational solutions
Quote:
Originally Posted by klbevan View Post
I'm trying to find the lengths of A and B in the photo. Any help?
SkipJack's got it. Basically, you exploit the fact that the angles for the little triangle and the big triangle are the same, so if $\displaystyle \theta$ is the angle at the top-right bit of the triangle, you then have

$\displaystyle \tan \theta = \frac{13312}{A}$

for the small triangle and

$\displaystyle \tan \theta = \frac{13744}{(1086+A)}$

for the large triangle. Equating the two gives

$\displaystyle \frac{13312}{A} = \frac{13744}{(1086+A)}$

which can then be solved for A using basic algebra. Once A is known, you can either use trigonometry or Pythagoras' theorem to get B using the small triangle dimensions.
Benit13 is offline  
Reply

  My Math Forum > High School Math Forum > Trigonometry

Tags
calculation, missing, side



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Integral calculation based on coordinates / Area under Curve calculation joskevermeulen Calculus 1 December 29th, 2015 06:02 AM
Side/Side/Angle SSA roketmike Trigonometry 3 July 16th, 2014 09:04 PM
Missing side of a triangle manich44 Algebra 8 March 19th, 2010 09:56 AM
missing? metallica fish Advanced Statistics 0 August 24th, 2009 02:21 PM
What am I missing here? brunojo Number Theory 1 June 15th, 2009 08:35 PM





Copyright © 2017 My Math Forum. All rights reserved.