01
Press these keys
SIN→COS→2nd→COS→√
Step 1 of 5. Press SIN.
02
Walkthrough
- 1Label opposite pairs
Match side a with angle A, and so on.
- 2Choose a rule
Use sine rule with a known opposite pair; cosine rule for SAS or SSS.
- 3Check geometry
Angles sum to 180° and inverse sine can have a second feasible angle.
03
Worked example
Given a=7, b=9 and C=60°, find c.
NORMAL FLOAT AUTO REAL MP
√(7²+9²−2·7·9·cos(60))8.185352772Answerc≈8.19.