Question 1

How can I check if a corner is square?

Accepted Answer

Use the 3-4-5 rule: measure 3 units along one side and 4 along the other; the diagonal should be exactly 5.

Question 2

Can I find the area if I know two sides and the angle between them?

Accepted Answer

Yes: area = ½ab sin C.

Question 3

Why is 3-4-5 called a Pythagorean triple?

Accepted Answer

Its whole-number sides satisfy a² + b² = c². Others include 5-12-13 and 8-15-17.

Your numbers