Teaching Algebra with Manipulatives

NAME ______________________________________________ DATE ____________ PERIOD ____
Algebra Activity Recording Sheet
(Use with the Lesson 11-7 Preview Activity on page 622 in the Student Edition.)
Investigating Trigonometric Ratios
Materials:
ruler, grid paper, protractor
Collect the Data
Use the table to record your data.
Side Lengths Ratios Angle Measures
side BC side AC side AB BC:AC BC:AB angle A angle B angle C
3.5 5 90°
7 10 90°
14 20 90°
90°
90°
90°
Analyze the Data
1. Examine the measures and ratios in the table. What do you notice?
Write a sentence or two to describe any patterns you see.
Make a Conjecture
2. For any right triangle similar to the ones you have drawn here, what
will be the value of the ratio of the length of the shortest leg to the
length of the longest leg?
Algebra 1—Chapter 11
3. If you draw a right triangle and calculate the ratio of the length of the
shortest leg to the length of the hypotenuse to be approximately 0.573,
what will be the measure of the larger acute angle in the right triangle?
© Glencoe/McGraw-Hill 191 Teaching Algebra with Manipulatives