An angle measuring 89 degrees is also an acute angle.
Visualization:
To visualize an acute angle, imagine a clock. The space between the minute hand and the hour hand when the time is between 12:00 and 3:00 forms an acute angle.
Know commonly used fractions (halves, thirds, fourths, fifths, eighths, tenths) and their decimal and percent equivalents. Convert between any two representations (fractions, decimals, percents) of positive rational numbers without the use of a calculator.