only acute angles can be complementary
Draw lines to connect up five pairs of complementary angles.
You’ll have two lonely single angles left over. Can you work out their complements?
46º + 44º = 90º
52º + 38º = 90º
40º + 50º = 90º
79º + 11º = 90º
63º + 27º = 90º
This angle doesn’t have a
complement because it is
already bigger than 90º!
90º - 9º = 81º, so the complement
of this angle would be 81º.
Did this sur
How can I tell which angles do and
don’t have a complement?
A:Only acute angles—angles less than
90º—can be complementary. An obtuse
angle is already greater than 90º on its own.
Why doesn’t 102º have a negative
complement of –12º? Surely that would
add up to 90º?
A:Complements can never be negative.
There’s no real reason for this except that the
term “complementary” means two positive
angles which add up to 90º.
angles can be
10 Chapter 1