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Let's do this question, find X in the following figure was the video, give it a try and then let's

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do it together.

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All right, we're back.

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Let's do it together over here.

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This is a five sided polygon, right?

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You have the DC, CB and B it.

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So it's a five sided polygon.

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Now, we know that the sum of interior angles is five sided.

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Polygon is equal to N minus two into 180.

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That's five minus two, which gives you three and three in two 180.

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Right.

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All right.

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Let me name these angles over here.

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This is angle to this is three.

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This is four and this is five.

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All right.

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Now, angle two is equal to 90 degree because of a linear pair.

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Right.

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It's forming a linear pair with angle 80 F over here, angle E, F plus angle two should be 180 degrees

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because it's a linear pair and it's given that angle F is equal to 90 degrees.

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Therefore, angle two is equal to 90 degrees.

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All right.

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So we've got that over here.

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Now let's try to find angle three.

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And three and this Angola, we hear it all also from a linear right, because it's a straight line,

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therefore angle three is equal to 180 minus 60, which is equal to 120 degree will be no angle to be

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no angle three.

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And this angle over here is 90 degrees.

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All right.

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Now, what about angle for angle four and 40 degree?

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This angle over here also form a linear right.

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Therefore, angle four is equal to 180, minus 40.

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That's equal to 140 degree.

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But we have this angle also.

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Now, let me call this angle as angle six.

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Now you can see that angle six plus angle two plus angle three plus angle five plus angle four.

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That's the five angles of this five sided polygon that would be equal to three to 180.

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Right now we have all the angles except angle five.

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So let's right the values for 90 plus 90 plus 120 plus five plus one forty five.

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Forty three in the one it is five forty.

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So solving this you can find that angle five is equal to under degrees right now, angle five and X

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on a linear pair, therefore angle five plus X is equal 180 degree and hence X is equal to eighty degrees.

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And that is the solution to this question.