Which equation can be used to find the unknown length, a, in this triangle?
15 m
17 m
3+15² = 172
152 +172 - a
2² +15= 172
at 15² = 17²

Here is the complete question.(attachment)

The correct choice is

Step-by-step explanation:

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

Pythagoras formula

The right angle is formed between and length.

So is the hypotenuse opposite to right angle is the longest side and called the hypotenuse.

So

So the measure of side length is .

That can be calculated from the option A that is .

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

sas (side angle side)

aa (angle angle)

sss(side side side)

sas find two sides with an angle in between

aa is finding two angles and the third will add up to 180

sss find all sides

step-by-step explanation: