Question

Which equation can be used to find the unknown length, a, in this triangle?

Answer 1

Answer:

Here is the complete question.(attachment)

The correct choice is $a^2+15^2=17^2$

Step-by-step explanation:

We will apply the Pythagoras formula to calculate the perpendicular length (a).

Pythagoras formula $=(base)^2+(perpendicular)^2=(Hypotenuse)^2$

The right angle is formed between $a$ and $15\ m$ length.

So $17\ m$ is the hypotenuse opposite to right angle is the longest side and called the hypotenuse.

So

$(a)^2+(15)^2=17^2$

$a=\sqrt{17^2-15^2}= 8\ m$

So the measure of side length $a$ is $8\ m$.

That can be calculated from the option A that is $(a)^2+(15)^2=17^2$.

Note:Please don't look to the marked answers that was wrong in the attachment.