Which statement is true about a right triangle?
a. the two angles other than the right angle must be total 90 degrees
b. exactly two angles must be right angles
c. one angle must measure exactly 60 degrees
d. all three sides of a right triangle must be equal to each other

With #! i’ve tried to figure it out but i can’t.

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

Thomas is using a drawing program to complete a construction. which construction could he be completing? two perpendicular lines are drawn. inscribing an equilateral triangle in a circle inscribing a square in a circle inscribing a regular pentagon in a circle inscribing a regular hexagon in a circle