Work the numbers, not the pictures

When asked for the measure of angle x...

How many people are tempted to...

  a)...              

                        o

...answer   120   ? (Because "x" looks to be twice as big as 60)

       or          

                b)...

...get out a protractor and measure. (And, of course, find that the answer is not one of the 5 choices given.)

                            o

The answer is 30  . The little box at the bottom left                                                                       o

indicates that the two black lines form a 90   angle. 90 - 60 = 30.

The picture is drawn purposely to mislead you. Work the numbers, not the picture.

Some important things to remember are...

All straight lines are 180 degrees.

All interior angles of a triangle add up to 180 degrees.

All interior angles of squares and rectangles add up to 360 degrees.