How would I answer this question?

Original post by JackT2000

Heres the question

(edited 7 years ago)

Reply 2

Opposite angles are congruent, that is 5x-20 = 2x+43 and the sum of interior angles is 360 degrees.

Reply 3

Original post by NotNotBatman

Opposite angles are congruent, that is 5x-20 = 2x+43 and the sum of interior angles is 360 degrees.

5x - 20 = 2x + 43 (-2x)

3x - 20 = 43 (+20)

3x. = 63 (/3)

x = 21

Reply 4

Original post by JackT2000

5x - 20 = 2x + 43 (-2x)

3x - 20 = 43 (+20)

3x. = 63 (/3)

x = 21

Correct.

Reply 5

Original post by NotNotBatman

Correct.

Ok now how would I find the value of X and y for the other pair of opposite angles

Reply 6

Original post by JackT2000

Ok now how would I find the value of X and y for the other pair of opposite angles

There is only one value of x, x=21. Use the fact that the interior angle sum is 360 in a quadrilateral and substitute x=21.

Reply 7

Original post by NotNotBatman

There is only one value of x, x=21. Use the fact that the interior angle sum is 360 in a quadrilateral and substitute x=21.

There is a missing angle though ?

Reply 8

now that you know x you can work out 2 angles exactly. the other 2 are equal to each other, and the total of the 4 angles is 360 degrees.

Reply 9

Original post by JackT2000

There is a missing angle though ?

diagonally opposite angles are equal.

Reply 10

Original post by the bear

now that you know x you can work out 2 angles exactly. the other 2 are equal to each other, and the total of the 4 angles is 360 degrees.

5(21) - 20 = 85
2(21) + 43 = 85

Now what do I do ?

Reply 11

Original post by JackT2000

5(21) - 20 = 85
2(21) + 43 = 85

Now what do I do ?

consider the total of the angles in a Quadrilateral

Reply 12

Original post by the bear

consider the total of the angles in a Quadrilateral

I don't understand

Reply 13

the 4 angles add up to 360 degrees.

Reply 14

Original post by the bear

the 4 angles add up to 360 degrees.

Yeah I know that but there is a missing angle and I don't know what it is?

Could you show me the full workings for this question please?

Reply 15

Original post by JackT2000

Yeah I know that but there is a missing angle and I don't know what it is?

Could you show me the full workings for this question please?

Sadly this is forbidden. We can only give hints along the way ?

:redface:

Reply 16

dnr_23

Original post by JackT2000

Yeah I know that but there is a missing angle and I don't know what it is?

Could you show me the full workings for this question please?

you said so yourself, opposite angles are equal. therefore if there is a missing angle, take a look at the opposite angle, and it will be the same!

Reply 17

85 + 85 + ? + ? = 360

Reply 18