Question:
Find the complement of each of the following angles.
(i) $55^{\circ}$
(ii) $16^{\circ}$
(iii) $90^{\circ}$
(iv) $\frac{2}{3}$ of a right angle
Solution:
Two angles whose sum is $90^{\circ}$ are called complementary angles.
(i) Complement of $55^{\circ}=90^{\circ}-55^{\circ}=35^{\circ}$
(ii) Complement of $16^{\circ}=(90-16)^{\circ}=74^{\circ}$
(iii) Complement of $90^{\circ}=90^{\circ}-90^{\circ}=0^{\circ}$
(iv) $\frac{2}{3}$ of a right angle $\Rightarrow\left(90 \times \frac{2}{3}\right)^{\circ}=60^{\circ}$
Complement of $\frac{2}{3}$ of a right angle $=(90-60)^{\circ}=30^{\circ}$