Find the Missing Angles & Side of this Scalene Triangle | Step-by-Step Tutorial

[haofengxd]

yo hello sir is me again, the guy who always support you :)

[illyriumus]

Thank from someone who is old enough to have forgotten the sn and cos formulas 😂. Very helpful though for us as parents that have kids and want to help our youngsters with math! Appreciated it a ton!

[bentramell]

So this isn't working out right for me, I'm trying to find the slope of a scaline triangle which is basically a roof, the rise is 4ft the run is 20ft, which conjoin at a right angle at 45⁰

So c²=a²+b² - 2(a)(b)cos45⁰
C²= 20²+4² - 2(20)(4)cos45⁰
C²=400+16 - 160cos45⁰
C²=416 - 160(.707)
C²=416 - 113.12
C²= 302.88
C =17.4
Problem with that is by this calculation, the slope is shorter than the run which cannot be the case.

Where am I going wrong here?

Wait I think I just answered my own question. It's 90⁰ angle duh not 45

[theoyanto]

This was immensely enjoyable, geometry is a true wonder, and you my friend demonstrate this wonder in a relaxed and stylish way that draws student back time and time again.
Geometry, where nothing stands alone but is always related in some magnificent way to its neighbours. Who can say with any certainty that we know all of geometry, there's lots more I'm sure. We are dealing with 2D here which is challenging enough for me.
Its as if geometry were a language and you are a native speaker, thank you for all your efforts, each day 👍🏻

[sameerqureshi-khcc]

Sir you are a MATHEMAGICIAN! Love from Pakistan 😊👍🌹

[JohnChristPagdonsolan]

Can I find the angle beta without trying to add all of the angles?

[susennath]

Monty North gives us an another way to solve the sum.

It is also excellent and from very basic elementary level.

Even it may be at 9 th level

I appreciate him/her

[montynorth]

Drop a perpendicular from point A to line CB and call intersection point P.
AP = 8 Sin 58 = 6.784
CP = 8 Cos 58 = 4.239
PB = 11-4.239 = 6.761
Tan Beta =6.784/6.761 = 1.0034
Beta = 45.1
Alpha = 180-58-45.1 = 76.9
Sin 45.1 = AP/c
c = AP/Sin 45.1 = 6.784/0.7083 = 9.58

[akbartamboli]

Dear Sir

Thank you for the easy explanation

Regards

[mustafizrahman]

alpha= 76.9 degrees, beta= 45.1 degrees, c= 9.58 units. I have solved it in the cosine theorem. This theorem is not my level because I am in 10th grade but I have learned 11th and 12th grades mathematics from 11th-12th grade books.

[mahalakshmiganapathy]

using law of cosine and sine formuae nice to watch

[devondevon]

Using ASA (law of cosine )
answer 9.578. 45.1 degree and 76.9 degree

[aymanyoutub]

I’m from morrocco, we study mathématique en frensh

[МихаилПрокоп-шы]

Theorems the cosines and sinus. Angel of the b= 180-58-a

[theophonchana]

c^(2) = (121 + 64 - 176) × cos (58°)
c^(2) = 185 - 176 × cos (58°)

[JohnChristPagdonsolan]

Can I find the angle beta without trying to add all the angles?