# Reaction forces in a pin jointed frame

This is the question: http://i.imgur.com/Ex2Yx4l.png

I have calculated all the angles in the frame, and have drawn line of forces so that the reaction force at x, reaction force at y, and the 10KN meet up. From then I am stuck, and dont know how to find the angle theta. http://i.imgur.com/gob3Cos.png

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BvU
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2019 Award
Hello Toodles, welcome to PF !

And this is the template:

## The Attempt at a Solution

(You must have deleted it by accident -- something that PF rules don't allow !)

What about this Bow's notation hint ? I only see a few red lines, but I don't believe I see any conditions for static equilibrium worked out ?

haruspex
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Gold Member
dont know how to find the angle theta.
Sometimes it's easier if you plug in a length. What you plug it doesn't matter since it won't affect the angle.
Say the distance between the anchor points, X and Y, is 1.
What is the length of the vertical line up from Y to (let's call it) A?
How long is the line that rises at 30 degrees from A to where it meets the 10kN line at (say) B?
How far is it from A to the vertical line through the load?
How far is it from X to the vertical line through the load?
How high is the topmost point (C) from the baseline?
Etc.