Question

What is the meaning of the following symbol in a triangle?
$\angle $
(a) degree
(b) angle
(c) congruent
(d) similar

Answer 1

Hint: We will first look at the definitions of the terms given in the options along with the way these are denoted. We will be able to get the correct answer from looking at the notations of the given options. We will look at the different types of angles and their definitions.

Complete step by step answer:
We know that degree is the unit of measurement of an angle. The symbol of degree is a small circle like this ${}^\circ $.
The definition of an angle is stated as a figure formed by two rays sharing a common endpoint. The two rays are the sides of the angle and the common endpoint is the vertex. The angle is denoted as $\angle $ along with the label of the vertex or along with the three points that represent the rays and the common vertex.
The term congruence is defined as coinciding exactly when superimposed or as identical in form. The symbol $\cong $ represents two objects to be congruent.
We say that two objects are similar when they have the same shape with the same angles and proportions, though of different sizes. We indicate the similarity of two objects by the symbol $\sim $.
From the definitions of the terms in the options and their symbols, we can conclude that the given symbol is the symbol of an angle.

So, the correct answer is “Option B”.

Note: There are different types of angles. If the angle is $90{}^\circ $, it is called a right angle and it has a special notation given by the symbol ∟ . An angle which is less than $90{}^\circ $ is called an acute angle. If the angle is greater than $90{}^\circ $, then it is called an obtuse angle. A straight angle is the angle which is exactly $180{}^\circ $.