Math questions. Pre algebra. Need Help please

Question

owlfred · Answer

Hoot! You just asked your first question! Hang tight while I find people to answer it for you. You can thank people who give you good answers by clicking the 'Good Answer' button on the right!

anonymous · Answer

Just post question.

anonymous · Answer

ok

anonymous · Answer

7.   Which of the following could NOT be the lengths of the sides of a right triangle?

9ft 12 ft and 15ft
5in 10in and 15in
4cm 7.5cm and 8.5cm
1.5m 2m and 2.5 m

anonymous · Answer

Check with pythagorean theorem.

anonymous · Answer

Sorry I am really bad at math can you please explain it to me.

anonymous · Answer

In each, the big one is c, the others a and b.$$c ^{2}=a ^{2}+b ^{2}$$

anonymous · Answer

I'm sorry?

anonymous · Answer

sorry didn't mean to put that

anonymous · Answer

ok

anonymous · Answer

Choice B? Because 5in + 10in = 15in (c)

anonymous · Answer

hello?

anonymous · Answer

Do you see the little 2 above the letters, I wrote above?

anonymous · Answer

yes

anonymous · Answer

Texas: What you want to do is use the Pythagorean theorem which states:
$$a^2+b^2=c^2$$.
Where a and b are legs of the triangle and c is the hypotenuse.
The hypotenuse is ALWAYS the largest side (i.e., your c value).
So try the numbers plugging them in.
I'll do one for you:
Choice A is 9,12,15.
So:
(9*9)+(12*12)=(15*15)
81+144=225
225=225. 
So choice A IS a possible right triangle.