…and this marking
ogether to make this angle…
18º + 72º = 90º
or you could jus
ll the magnets y
o find one that fits—making 90º.
angle magnets solution
Angle Magnets Solution
Which of these angles matches the mystery angle?
62º 72º 45º
18º + ?º = 90º
ight angle = 90º.
We know that these tw
ou could hav
e done 90–18 t
o find the 72º,
I checked that mystery angle with a protractor and it
wasn’t 72º—so how come you’re saying it is?
A:In geometry, unless you’re specifically told to measure
an angle, assume that the drawing isn’t accurate, but that the
numbers on the sketch are. We calculate missing angles rather
than measure them.
What about all the other lines on the diagram? Do we
know if they’re straight?
A:The other line segments on the sketch represent things
like walls or the path between two points. They’re all definitely
straight. In fact, the two line segments we’re interested in—the
bullet path and the path from Benny to Micky—are also straight.
What we need to find out is whether they join up to form one
single straight line.
Chapter 1 8