Write four true conditional statements based on this biconditional statement. An angle is a right angle if and only if it measures 90°.

The four true statements are:

1. If an angle is a right angle,  it measures 90°.

2. If an angle measures 90°, it is a right angle.

3. If an angle is not a right angle,  it does not measure measure 90°.

4. If an angle does not measure 90°, it is not a right angle.

Step-by-step explanation:

Given the biconditional statement:

An angle is a right angle if and only if it measures 90°.

To find:

Four true conditional statements.

Solution:

First of all, let us the learn the concept of four true conditional statements from a given biconditional statement.

Let the biconditional statement be " is true if and only if is true.

Then the four true statements can be written as:

1. If is true then is true.

2. If is true then is true.

3. If is false then is false.

4. If is false then is false.

Here is "an angle is a right angle"

is "it measures 90°" .

So, the four true statements are:

1. If an angle is a right angle,  it measures 90°.

2. If an angle measures 90°, it is a right angle.

3. If an angle is not a right angle,  it does not measure measure 90°.

4. If an angle does not measure 90°, it is not a right angle.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.