Look at the photo frame
Which statement is true about the photo frame?

Multiple choice:
It is rectangular because the diagonal is less than the sum of 21 and 13
It is not rectangular because diagonal DB bisects angle ADC and angle ABC
It is not rectangular because the sum of 13 squared and 21 squared is not equal to 23 squared
It is rectangular because side DC meets side BC at 90 degrees

Question

Look at the photo frame
Which statement is true about the photo frame?

Multiple choice:
It is rectangular because the diagonal is less than the sum of 21 and 13
It is not rectangular because diagonal DB bisects angle ADC and angle ABC
It is not rectangular because the sum of 13 squared and 21 squared is not equal to 23 squared
It is rectangular because side DC meets side BC at 90 degrees

anonymous · Answer

attachment

anonymous · Answer

does this question use pythagorean theom?
Sorry for my horrible spelling lol

anonymous · Answer

Yes. To prove it's rectangular, you need to prove that the angle in the corner is 90 degrees, and the easiest way to do that is to show that the pythagorean theorem works with 13, 21, and 23.

anonymous · Answer

do you do that by squaring them and then finding the square root ?

anonymous · Answer

Yup.  All pythagorean theorem problems are essentially the same thing.