Question

An angle which measures $90^\circ $ is called
A) Obtuse
B) Acute
C) Right
D) None of these

Answer 1

Hint:In this question we ask about the name of the angle which measures $90^\circ $. Recall the different types of angles of the triangle on the basis of angle measurement, you will get your answer.

Complete step-by-step answer:
We are given that a measure of an angle which is $90^\circ $
We have to find the name of that triangle.
There are different types of angles in a triangle.
We will check each option one-by-one.
Option-A
In this option the name of the angle is obtuse.
The measure of an obtuse angle is greater than $90^\circ $ and the triangle which contains an obtuse angle is called an obtuse-angled triangle.
So, this option cannot be our answer.
Moving to the next option.
Option -B
In this option the name of the angle is acute.
The measure of an obtuse angle is less than $90^\circ $ and the triangle which contains an acute angle is called an acute-angled triangle.
So, this option cannot be our answer.
Now we check option (C)
Option-C
In this option the name of the angle is right.
The measure of a right angle is $90^\circ $ and the triangle which contains a right angle is called a right-angled triangle.
So, this option will be our answer.

Therefore, option (C) is correct.

Note:
As in our question we discussed the name of the angle which measures $90^\circ $ and a right-angled triangle. In the right-angled triangle we can use the Pythagoras theorem to evaluate the length of the sides.
Pythagoras theorem states that the square of the hypotenuse is equal to the sum of the squares of the base and altitude.