# What is the measurement of side a?

### 12 Answers

- RRLv 71 month agoFavorite Answer
The Pythagorean theorem, states that the square of the length of the hypotenuse is equal to the sum of squares of the lengths of other two sides of the right-angled triangle.

a^2 + 9^2 = 12^2

a^2 = 12^2 - 9^2

a^2 = 144 - 81

a^2 = 63

a = 7.94

- Jim MoorLv 71 month ago
That "appears" to be a Right Angle, but that is not specified. What if it was 91 degrees???

So from the info given YOU CANNOT BE SURE OF AN ANSWER.

IF they told you it's 90 degrees (a Right Triangle), then use Pythagoras.

- Log in to reply to the answers

- What do you think of the answers? You can sign in to give your opinion on the answer.
- ComoLv 71 month ago
a² = 12² - 9²

a² = (12 - 9) (12 + 9)

a² = 3 x 21

a = √3 x √21

a = √63

- Log in to reply to the answers

- Iggy RockoLv 71 month ago
Use the Pythagorean Theorem.

a^2 + 9^2 = 12^2

a^2 + 81 =144

a^2 = 63

a = √63

- Log in to reply to the answers

- DavidLv 71 month ago
Using Pythagoras' theorem side 'a' is 3 times square root of 7 or about 7.94

- Log in to reply to the answers

- PopeLv 71 month ago
You have given the lengths of two sides of a triangle, but have given no angles. No, there is no right angle in the given conditions. The best we can do is this inequality.

12 - 9 < a < 12 + 9

3 < a < 21

- Log in to reply to the answers

- Govind 3iLv 41 month ago
Hypotenuse is 12

==> 12^2 = 9^2 + a^2

==> 144 = 81 + a^2

==> 144 - 81 = a^2

==> 63 = a^2

==> a = 8( approx)

- Log in to reply to the answers

Thank you!