Types of Aangles (Right, Acute, Obtuse, Flat): Identifying and defining elements

Examples with solutions for Types of Aangles (Right, Acute, Obtuse, Flat): Identifying and defining elements

Exercise #1

True or false?

One of the angles in a rectangle may be an acute angle.

Video Solution

Step-by-Step Solution

One of the properties of a rectangle is that all its angles are right angles.

Therefore, it is not possible for an angle to be acute, that is, less than 90 degrees.

Answer

False

Exercise #2

True or false?

An acute angle is smaller than a right angle.

Step-by-Step Solution

The definition of an acute angle is an angle that is smaller than 90 degrees.

Since an angle that equals 90 degrees is a right angle, the statement is true.

Answer

True

Exercise #3

Choose the appropriate triangle according to the following:

Angle B equals 90 degrees.

Video Solution

Step-by-Step Solution

Let's note in which of the triangles angle B forms a right angle, meaning an angle of 90 degrees.

In answers C+D, we can see that angle B is smaller than 90 degrees.

In answer A, it is equal to 90 degrees.

Answer

AAABBBCCC

Exercise #4

Which figure depicts a right angle?

Video Solution

Step-by-Step Solution

A right angle is equal to 90 degrees.

In diagrams (a) and (c), we see that the angle symbol is a symbol representing an angle that equals 90 degrees.

Answer

Exercise #5

Which of the following angles are obtuse?

Video Solution

Step-by-Step Solution

By definition, an obtuse angle is an angle that is greater than 90 degrees. We can see that in one drawing there is an angle of 90 degrees and therefore it is not an obtuse angle, the other two angles are less than 90 degrees meaning they are also not obtuse, they are acute angles.

Therefore, none of the answers is correct.

Answer

None of the options

Exercise #6

If the two adjacent angles are not equal to each other, then one of them is obtuse and the other acute.

Video Solution

Step-by-Step Solution

The answer is correct because the sum of two acute angles will be less than 180 degrees and the sum of two obtuse angles will be greater than 180 degrees

Answer

True

Exercise #7

True or false?

The sum of two acute angles can be greater than 180 degrees?

Video Solution

Answer

False.

Exercise #8

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true

Exercise #9

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true

Exercise #10

Which of the angles is not an obtuse angle?

Video Solution

Answer

Exercise #11

Which of the following angles is a plane angle?

Video Solution

Answer

Exercise #12

Which of the following angles is straight?

Video Solution

Answer

Exercise #13

Which of the following angles is obtuse?

Video Solution

Answer

91°

Exercise #14

Which of the following angles is obtuse?

Video Solution

Answer

Exercise #15

Which figure shows a right angle?

Video Solution

Answer

Exercise #16

Does the drawing show an adjacent angle?

Video Solution

Answer

True

Exercise #17

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true

Exercise #18

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true

Exercise #19

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true

Exercise #20

Does the drawing show an adjacent angle?

Video Solution

Answer

Not true