Question

help

Answer 1

A student writes an incorrect step while checking if the sum of the measures of the two remote interior angles of triangle ABC below is equal to the measure of the exterior angle.

A triangle ABC is shown. The base of the triangle extends into a straight line. The angle formed between this straight line and the edge of the triangle is marked as w. The angle adjacent to w is marked as z, and the other two angles inside the triangle are marked as x and y.

Step 1: m∠x + m∠y + m∠z = 90 degrees (sum of adjacent angles)
Step 2: m∠w + m∠z = 180 degrees (supplementary angles)
Step 3: Therefore, m∠x + m∠y + m∠z = m∠w + m∠z
Step 4: So, m∠x + m∠y = m∠w

In which step did the student first make a mistake and how can it be corrected?

Step 1; it should be m∠x + m∠y + m∠z = 180 degrees (sum of angles of a triangle)
Step 1; it should be m∠x + m∠y + m∠z = 180 degrees (corresponding angles)
Step 2; it should be m∠w + m∠z = 90 degrees (supplementary angles)
Step 2; it should be m∠w + m∠z = 90 degrees (adjacent angles)

Answer 2

@AlexandervonHumboldt2

Answer 3

@freckles

Answer 4

@ganeshie8

Answer 5

@ParthKohli

Answer 6

@phi

Answer 7

@whpalmer4

Answer 8

@AlexandervonHumboldt2

Answer 9

which do you think the answer is?

Answer 10

b

Answer 11

close, you are right in that the error was made in step 1, but the reasoning isn't quite there..

Answer 12

ohhh so its c

Answer 13

do you understand what corresponding angles are?

Answer 14

No, c indicates that step 2 is the one with the error..

Answer 15

yes i do what do you think the answe might be and ok

Answer 16

can you explain?

Answer 17

I believe it is A because see how they said in step 1 " m∠x + m∠y + m∠z = 90 degrees (sum of adjacent angles)" but when you look at the diagram, the angles indicated are actually the internal angles of the triangle..

Answer 18

And in geometry, the sum of the internal angles of a triangle is always 180º, so m∠x + m∠y + m∠z must = to 180, not 90, because its the sum of the interior angles of the triangle

Answer 19

does that make sense?

Answer 20

oh ok ok can you help me with a few more maybe and yes it does (:

Answer 21

sure! :)