Question

On a recent test, Shawna was given the following problem:

Shawna's work is shown below:
1. a2+72=252
2. a2+14=50
3. a2=36
4. a=6 m

In which step did Shawna make an error?
Step 1. She incorrectly applied the Pythagorean theorem.
Step 2. She incorrectly squared the numbers.
Step 3. She incorrectly isolated a2
Step 4. She incorrectly solved for a.

Answer 1

Since, we are given right angled triangle

so, we use pythagoras theorem to find 'a'

step-1:

Using pythagoras theorem

`a^2+7^2=25^2`

step-2:

we know that

`7^2=7* 7 =49`

`25^2=25* 25 =625`

so, we get

`a^2+49=625`

she made error in second step

step-3:

Subtract both sides by 49

`a^2+49-49=625-49`

`a^2=576`

step-4:

Take sqrt both sides

we get

`a=24`

so,

Answer is:

Step 2. She incorrectly squared the numbers.

Answer 2

Answer: Step 2. She incorrectly squared the numbers.

Solution:

The correct steps are:

1. a^2+7^2=25^2

2. a^2+49=625

3. a^2=576

4. a=24

In which step did Shawna make an error?

Step 2. She incorrectly squared the numbers.