for a mathematical statement to be an equation, the quantities on each side of an equal sign must be?

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

Acompany charges $0.10 for each letter engraved. bobby plans to spend no more than $5.00 on the engraving on a jewelry box. write and solve an inequality to find the maximum number of letters he can have engraved.

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle