Writing a proof to prove a parallelogram is a rectangle

👉 Learn how to solve problems with rectangles. A rectangle is a parallelogram with each of the angles a right angle. Some of the properties of rectangles are: each pair of opposite sides are equal, each pair of opposite sides are parallel, all the angles are right angles, the diagonals are equal and bisect each other, etc.

Given expressions representing some of the parts of a rectangle, we can evaluate the expressions using our knowledge of the properties of a rectangle.

Organized Videos:
✅Quadrilaterals
✅Properties of Parallelograms
✅Properties of Rhombuses
✅Properties of Kites
✅Quadrilaterals on a Coordinate Plane
✅Properties of Rectangles
✅Properties of Trapezoids

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#Quadrilaterals #brianmclogan

[madeleine]

this made me feel like i’m back in in-person school 🤦‍♀️

[janediceplier]

Statement: It's a rectangle
Reason: by the definition of a rectangle






im gonna lose my mind this did not help

[Oogaboogasuga]

So for the problem given to me, it gives that the two diagonals are congruent and that the shape is a rectangle. What should I write to prove that it is a parallelgram? In the video, once you proved the two diagonals were congruent, you wrote that it was a rectangle because of the definition of a rectangle. I just don't know how, or if I need to write more.

[HistoryChef]

Also the fact that, RX=XT and UX=XS (given), angleRXS=angleUXT as they are vertically opposite angles. hence since the triangles are congruent by SAS, the opposite sides are equal, and hence its a rectangle, I think this is more appropriate.

[CharlieZena]

Geometry teacher here: this video does not align with the thumbnail. Its not given that all four parts are congruent. Its only given bisections of each diagonal at x.

[douglee]

Why was step 2 needed (checking the lengths from corners to the center) which can only be determined by the missing step of determining the center? Just start with: Is the length of RT the same as the length of SU... If they're are equal, then it's a rectangle, if they're not equal then it a parallelogram. And what about ensuring that the lengths of opposing sides are equal?

[ashg.]

I see this a lot with congruence and equality. I believe there is a reason for the definition of congruence so you can switch to equality and back to congruence again. Before using the segment addition postulate I should first switch everything to equality.

RX = TX = SX = UX then go on to use the segment addition postulate for
RX + TX = RT and SX + UX = SU. Then use substitution property to get
TX + TX = RT and SX + SX = SU then
Substitute again to get
2TX = RT and 2SX = SU we know
SX = TX so use substitution to get
2TX = RT and 2TX = SU, then the symmetric prop of equality to get
RT = 2TX and 2TX = SU. Now use the transitive prop of equality (or substitution) to get
RT = SU.
Now we can say segment RT is congruent to segment SU by definition of congruence.
Therefore, parallelogram RSTU is a rectangle because you have a parallelogram with congruent diagonals. QED

I feel like the one kid was confused because you skipped a lot of steps and implied a significant amount.

I like some of your videos and I swear you have the exact same shirt as me lol.

[LS_RAPR]

I need someone like u who can talk to me my maths teacher doesn't make me understand anything but u on the other hand u are a quality teacher👏

[sahasratutorials]

How can you say that RX=SX it is not possible because given quadrilateral is a parallelogram..

[jeremiavili]

Can you plz pût again some video likethis about a rhombus

[whenthepotatodances]

Thanks for the help. Or else I might have been grounded tomorrow in my maths class.

[peterlai]

He didn't proof that its had four right angle or may be he didn't get the definition of rectangle.

[kbfunshorts]

How you can say that the diagonal is equal in parallogram. This shows that you don't know the properties of parallogram. Diagonal are bisect each other it mean that they cut each other in two equal parts

[makenakruper]

thank you for teaching me how to do this. i wish my teacher could.

[re-yoda]

but this could also mean it's a square right?

[HMCuber]

Thank you I'm in 9th grade taking geo. Advanced.

[anthonyz]

I don't understand his concept of "you can't put the 90 degree in the corner that proves it's 90 degrees, that's like me saying I'm 100 lbs." That completely goes against any math regarding figures

[saichannel]

Can't u take the parallelogram as ABCD which may be easy