Change in gravitional potential energy at an angle?

[flemj]

Homework Statement

A 0.23kg pendulum bob is attached to a string 1.2 long at an angle of 30 degrees. What is the change in the gravitational potential energy of the system as the bob swings from point A to point B
U=

Homework Equations

.5 mv^2 = mgl
U=E+K

The Attempt at a Solution

in the picture it looks like a string attached to a roof with the ball at rest touching the roof and swinging down to a position 35 degrees below I am just not sure how you use the angle of 35 in the problem

 

[Hootenanny]

Can you relate the change in angle to the change in height of the bob?

 

[flemj]

Can you relate the change in angle to the change in height of the bob?

the height isn't given its just the length of the string sorry.

 

[Hootenanny]

the height isn't given its just the length of the string sorry.

I know it isn't given, what I was saying is can you work it out using the angle and the length of the string?

 

[flemj]

I know it isn't given, what I was saying is can you work it out using the angle and the length of the string?

would you do that my x sin theta ?

im just really frustrated with this question

 

[Hootenanny]

would you do that my x sin theta ?

I'm not sure what my is meant to be, but yes you should use trigonometry.