# Math problems help. Geometry

#### Etrujillo

##### New member
If anyone can point me in the right direction please. For #3-5 can i create a triangle, out of all 3 problems, obviously #3 is already a right triangle. And apply pythagoras therom to solve for the other side? Then find the areaof the triangle and deduct that area from the total area of the circle to find ab?

for questions 1& 2 i am at a total loss. Any help and guidance would be greatly appreciated. Remember im learning. Thank you so much. Have a nice day.

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#### pka

##### Elite Member
If anyone can point me in the right direction please. For #3-5 can i create a triangle, out of all 3 problems, obviously #3 is already a right triangle. And apply pythagoras therom to solve for the other side? Then find the area of the triangle and deduct that area from the total area of the circle to find ab?
for questions 1& 2 i am at a total loss. Any help and guidance would be greatly appreciated. Remember im learning. Thank you so much. Have a nice day.
It is almost impossible to help you with any of your posts. We have no idea what sort of background you bring to the questions.
You are in 3 4 & 5 for $$\displaystyle S$$ the length of the arc $$\displaystyle AB$$ . In #3 the line segment from the center to the cord $$\displaystyle \overline{AB}$$ bisects it they are perpendicular. You say they are. But it is not given in the problem. If they are the half the length is $$\displaystyle \sqrt{7^2-4^2}$$. Now that is only for the chord. We do not know what else you know. The arc length is $$\displaystyle S=\theta R$$ where $$\displaystyle R=7$$ and $$\displaystyle \theta=\arcsin\left(\dfrac{4}{7}\right)$$ all of which which does you no good if you are not experienced in trigonometry.

We are here to help those who know. We are not here to teach new material.

#### Etrujillo

##### New member
When i joined this forum it didn’t specifically state you had to know math especially trigonometry somethig ive barely covered in my class. Rule of thumb if you don’t have anything nice to say don’t say nything at all. Thank you for you unhelpful input.

#### pka

##### Elite Member
When i joined this forum it didn’t specifically state you had to know math especially trigonometry somethig ive barely covered in my class. Rule of thumb if you don’t have anything nice to say don’t say nything at all. Thank you for you unhelpful input.
May I ask you if you understand that in the three questions you posted, $$\displaystyle 3,~4,~\&~5$$ they ask you to find the length of $$\displaystyle arc~AB$$.
It is your questions that introduce trigonometry not me. I simply pointed out what was required in order to do what you were assigned.

#### Dr.Peterson

##### Elite Member
If anyone can point me in the right direction please. For #3-5 can i create a triangle, out of all 3 problems, obviously #3 is already a right triangle. And apply pythagoras therom to solve for the other side? Then find the area of the triangle and deduct that area from the total area of the circle to find ab?

for questions 1& 2 i am at a total loss. Any help and guidance would be greatly appreciated. Remember im learning. Thank you so much. Have a nice day.
Let's try again, with a more positive start.

In #3, yes, you can use the Pythagorean theorem to find the other leg of the right triangle, which is half the chord. But you don't really need to do that to answer the question, which is not about segment lengths or areas, but about arc length, for which you will need to find the angle at the center of the circle. You'll have to use an inverse trigonometric function; please tell us what you know about doing that, and show whatever work you can do on it.

In #4 and #5, you can use the same technique, drawing the perpendicular yourself and using the fact that it divides the chord into equal parts.

For #1, sketch the figure, and use the fact that triangle WXT will be a right triangle. Then use the Pythagorean theorem.

For #2, sketch the figure, and label the length of ET "x". What is an expression for the length of EM? Then you can write an equation to solve for x.

The more information you give us about what you do know, and where you are stuck on a problem, the easier it is for others to help. See this summary of our submission guidelines, if you haven't already. That is, we know you're learning something, or you wouldn't be asking; but we don't know what you are learning, and what you have learned, unless you tell us. (It is a little confusing that you have some mere Pythagorean Theorem problems followed by some inverse trig/arc length problems, which are quite different.)