# Trig Help on 90 degree angle

ok as when I list all of my problems I just need ideas of where to start and go towards no the final answer though. The problem states:

A block of metal has a 90 degree notch cut from its lower surface. The notched part rests on a circular cylinder of diamter 2.0 cm. If the lower surface of the part is 1.3 cm above the base plane, how deep is the notch?

I have attached a file that shows the diagram. Any help would be appreciated.

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## Answers and Replies

tiny-tim
Homework Helper
A block of metal has a 90 degree notch cut from its lower surface. The notched part rests on a circular cylinder of diamter 2.0 cm. If the lower surface of the part is 1.3 cm above the base plane, how deep is the notch?
Hi ur5pointos2sl!

(I can't see the diagram yet, but …)

If the apex of the notch is A, and the notch touches the cylinder at T and U, the bottom of the notch (part of the lower surface) is B and C, and BC meets AO at D, and the centre of the cylinder is O, then draw the triangles AOT and ABD, and use trig.

Hi ur5pointos2sl!

(I can't see the diagram yet, but …)

If the apex of the notch is A, and the notch touches the cylinder at T and U, the bottom of the notch (part of the lower surface) is B and C, and BC meets AO at D, and the centre of the cylinder is O, then draw the triangles AOT and ABD, and use trig.
What exactly would the D be referring to? The line from B to O?

tiny-tim