Triangle angle example 2 | Angles and intersecting lines | Geometry | Khan Academy

Another example finding angles in triangles

Missed the previous lesson?

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[yahyasher]

it takes 5 seconds to do this problem, 121 + y = 180, y= 59, x is corresponding to y so they are congruent. Corresponding angles are congruent with or without parallel lines

[nicolemungai]

I've learned more here than in my 8 months in math class

[slutiva]

simplest is to see that the lines are parallel, due to the 29 degree angles, so 180 minus the exterior angle 121 gives the angle which is the same as x

[mohammadadnankhan]

Most helpful
Makes hard problems look easy

[AlexTheNiceGuy]

This can be simplified even further by simply just subtracting 121 from 180 (180 - 121 = 59) and applying it to x,

Thanks Sal!

[shahtajbaloch]

Thank you very much, God bless you. I am a science student learning maths for gre and its helping me greatly. Thank you very much.

[mubarikabdulahi]

Some thing wrong isn't 92° but it's 90 for two angles are meeting

[smileyjj]

But the rest spot on thanks for the help

[malielanijoy]

I think the fastest and simplest way is to just get 59 from 180-121. We know that the two diagonal lines are || (because when two lines are cut by a transversal and alternate interior angles are ≅, the lines are ||), so that means corresponding angles are ≅.

[atharvanagdeve]

This academy is the best. Guys please donate them cuz they r non profit. i have donated $25. plz you too

[azizbekvakhobov]

2 years of math in this 5 minute video

[smileyjj]

You made right triangles and claim it's 92

[notdaryl]

Or you can do 121 x 2 = 242, 360-242= 59 and since it is parallel that means X is 59

[mathematics-pt]

Please make it clear that why you use 92 instead of 90?

[NicholasGaming]

OK who here is on online school and from mrs. worrell's class help us leave comment if you are

[xiaozhonghe]

you could just have found the supplementary angle of 121 and the other side, which is 59, and because they are parallel lines you can just put 59 on the other side to get 59. Great video otherwise though!

[RudyEditz-]

bro just subract 180-121 cause they are co interior angles and they form linear pair and the answer is 59 degrees

[haider]

Don't tell me you learned this in primary school!😏

[_rileyweaver_]

Figured it out in 4 seconds. (I'm in 7th grade)

We have two lines, each with a 29-degree angle. That makes them parallel lines (I'm not explaining why). On the left side of the plane, one of the angles is 121 degrees, and since the two lines are parallel, that carries over to the other line, making 121+x=180 (supplementary angles). Simple math figures out the rest. None of that complicated stuff is required in this case, but its usually a good idea to know this, if the two lines' angles are not equal.

[brianbush]

he was wrong about the 92 degrees perpendicular lines intersect at a 90 degree angle so i solved it in under 30 seconds because 180-90-29=61