135 is correct. Bottom intersection is 80/100, 180-35-100 = 45 for the top of the second triangle. 180 - 45 = 135

This is a standard way to draw geometric proofs, it's not at all unreasonable to assume straight lines alongside unrepresentative angles. It's certainly still an assumption, but a conventional one.

I mean, the assumption shouldn't be anything about scale. It should be that we're looking at straight lines. And if we can't assume that, then what are we even doing.

But, assuming straight lines, given straight lines you find the other side of an intersecting line because of complements.

Stupid stuff like this is why kids hate math class. Unless the problem says calculate all unmarked angles, those visually 90 degree angles are 90 degrees. It works that way in any non engineering job that uses angles because it's common sense.

135°.

The non-right-angle is downright cheeky.

trash diagram too

A lot of those standardized tests like SAT or GRE like to put those in (or at least they used to) on purpose. It wasn't that they couldn't render the diagrams correctly, instead they were checking for people making assumptions with information that wasn't given. To be somewhat fair I seem to recall a disclaimer that they weren't necessarily drawn accurately.

It pisses me off to no end that what is CLEARLY shown as a 90degree angle is not in fact 90deg, I hate it when they do that.

Also I will sadly admit this can teach people lessons about verifying the information themselves.

^GrumbleGrumbleGrumble....^

Nah, the angle isn’t specified as a right angle. We can’t assume it’s 90° just because it’s drawn that way, because it isn’t drawn to scale.

Left triangle has 180° total. 60+40=100, which means that middle line is actually 80°, not 90. And since the opposite side is the inverse, we know it is 100° on the other side.

100+35=135. We know the right triangle also has 180° total, so to find the top corner we do 180-135=45. So that top corner of the right triangle is 45°, meaning x must be 135° on the opposite side.

There's perils in being in 3d

135° actually - left triangle has 40° and 60° which implies last angle is 80° not 90°

Wrong, as the drawing is not representative. The inner lower angle for the right triangle has to be 100°, as such the inner upper angle has to be 45° and the X angle has to be 135°.

It's a trap. The drawing is misleading. If the left triangle already has 60° and 40° then only 80° remains. Meaning there's no right angle. The vertical line should be leaning to the left slightly. The correct answer is 135°.

This is a standard way to draw geometric proofs, it's not at all unreasonable to assume straight lines and unrepresentative angles.