Tips For Success

Some problems require the selection of an appropriate representation (concrete, pictorial, graphical, verbal, or symbolic) to find a solution.

Tip 1

Make a drawing.

One angle of a right triangle measures 90°. The measure of the second angle is 5 times the measure of the third. What are the measures of these angles?

1. 30° and 60°
2. 30° and 150°
3. 15° and 75°
4. 20° and 100°

Tip 2

Write a system:

x + y + 90 = 180 x = 5 y table with 2 rows and 2 columns , row1 column 1 , x plus y plus 90 , column 2 equals 180 , row2 column 1 , x , column 2 equals 5 y , end table

Think It Through

A triangle can have only one right angle, so the other two angles must each have a measure less than 90°. Use x and y to represent the unknown angles.

x = 5 y

5 y + y + 90 = 180 6 y + 90 = 180 6 y = 90 table with 3 rows and 2 columns , row1 column 1 , 5 y plus y plus 90 , column 2 equals 180 , row2 column 1 , 6 y plus 90 , column 2 equals 180 , row3 column 1 , 6 y , column 2 equals 90 , end table

y = 15, x = 75

The correct answer is C.