Math help!

laushik · November 30, 2016

How do I solve this? I can't use Pythagoras theorm since there is only one side length that is known and I can't use sin cos tan because there is no target angle. Pls help:

TopDollar · December 1, 2016

They key to this is that the problem states that the figure is a "scale" diagram. You can determine the scale of the figure by measuring the "wall of dog house" with a ruler and comparing it to 2 m. For example, if the line is 4 inches long, then you know that every 4 inches on the figure equals 2 meters in real life (or 2 inches = 1 meter). Once you know that, you can measure the unknown leg of the dog run (I recommend the leg 90 degrees perpendicular to the known quantity). Say that you measure that leg and it turns out to be 6 inches long. Applying the scale you determined earlier (2 inches = 1 meter) tells you that the leg would be 3 meters long. Now that you know the two bases of the triangle, you could use Pythagorean theorem to determine the hypotenuse. Additionally, you could measure the hypotenuse with a ruler and check your answer with the scale determined in step one.

(**Note** I don't actually know if the line is 4 inches long; that was just an example. You will have to measure the line in your textbook to determine the real scale)

Shahnewaz · December 1, 2016

I don't think this can be solved mathematically without knowing at least one more side or an angle.

Are you sure the figure isn't drawn to scale?

charles899 · December 1, 2016

uh? isnt it a 90 degree angle meaning side a and side b is the same length meaning a^2+b^2=c^2 so 2m^2+2m^2=c^2?

dalekphalm · December 1, 2016

18 minutes ago, charles899 said:

uh? isnt it a 90 degree angle meaning side a and side b is the same length meaning a^2+b^2=c^2 so 2m^2+2m^2=c^2?

This is a false assumption, and a misunderstanding. The 90 degree angle doesn't mean anything, except that the two sides meet at that angle. It does NOT mean the OTHER angle is 45 degrees, which would be required for your assumption.

The two sides can still meet at a 90 degree angle, but one side can be 1.2 times as long, or 1.5, or 25 times, etc. The other two angles would just adjust as one side became longer.

@laushik as @TopDollar has said, you can easily solve for the answer because the "word problem" gave you the clues necessary to solve the equation. Specifically, that the diagram is to scale. In other words, break out your ruler, and measure all three sides.

Once you have those three measurements, you have the Scale Ration, since you take the measurement that you made of the Dog House wall, and compare it to the measurement given: 2m long

This is actually really easy math, because you don't even need to use Pythagoren's theorem. You just use the ratio to scale up the measurements of the two other sides at the same ratio as the measurement of the dog house vs the 2m measurement.

BTW @laushik you seem to be posting a LOT of homework questions on here, ones that aren't particularly complex math (And I assume are age appropriate for your grade).

Are you having trouble in your math/science classes? If so, dude, seriously, you need to go get a Tutor. You can't keep posting questions on here all the time, because:

1. If people just give you the answer, you won't learn how to get that answer, and

2. If you're actually struggling to complete these homework questions, nothing is going to help you more then getting an in-person tutor, who can measure your skill level, and tailor assistance directly to what you need.

2 hours ago, Shahnewaz said:

I don't think this can be solved mathematically without knowing at least one more side or an angle.

Are you sure the figure isn't drawn to scale?

Did you read the OP's question? This is a really easy math question. The diagram IS drawn to scale. It clearly says so in the word problem.