Question

can someone help me with geometry

Answer 1

whats your question?

Answer 2

i got 5 but i want you to help me do it if thats okay?

Answer 3

ok.

Answer 4

A triangular section of a lawn will be converted to river rock instead of grass. Maurice insists that the only way to find a missing side length is to use the Law of Cosines. Johanna exclaims that only the Law of Sines will be useful. Describe a scenario where Maurice is correct, a scenario where Johanna is correct, and a scenario where both laws are able to be used. Use complete sentences and example measurements when necessary.

Answer 5

thats question 1 i'll ask one after one so we can get this done easily

Answer 6

sorry. im not that great at these kind of word problems

maybe @marissalovescats can help?

Answer 7

Thanks anyways

Answer 8

Well a scenario where Maurice will be correct is if they gave you 2 sides of the triangle and the Angle of this missing side. This means you are able to use the law of cosines.

Answer 9

A scenario where Johanna is correct is if they gave you a side and an angle that correspond and another side/angle but asked for the corresponding depending on which they gave you.

Answer 10

c2 = a2 + b2 – 2ab cos(C)
b2 = a2 + c2 – 2ac cos(B)
a2 = b2 + c2 – 2bc cos(A)
\
for thefirst one?

Answer 11

Yes exactly. So if they gave sides b and c of the triangle, and angle A, we could solve with the law of cosines for side a with a^2=b^2+c^2-2(b)(c)cosA

Answer 12

And with Johanna, if they gave you the angle and side of A (or B) and only one angle/one side for angle B (or C) we would use:

Sin A/a=SinB/b or SinB/b=SinC/c

Answer 13

ok but the problem is they didn't give me any picture or anything they gave for question 1

Answer 14

actually let me check again

Answer 15

Well we don't need a picture, we can make our own problem.

And a case where we can use both is if we are given 2 sides and 1 angle we can use the law of cosine to find the 3rd side and then law of sine to find an angle

Answer 16

okay do you have skype so you can help me do it over there because i find it easier but if you don't its fine i can do it over openstudy

Answer 17

Okay so Example 1: Here is our triangle ABC (this will be for law of cosine) So we will be given 2 sides and 1 angle:

So lets say we are told side b is 12 and side a is 9 and angle C is 48 degrees.

We will use the Law of Cosine:

c^2=a^2+b^2-2(a)(c)CosC

c^2=9^2+12^2-2(9)(12)Cos(48)

Make sense?

Answer 18

For example two, same triangle:

Except this time we are told that Angle A is 56 side a is 10 and that Angle B is 42 and we want to find side b. We'd set up:

Sin(56)/10 = Sin(42)/b