Answer:
The flagpole is
4
meters tall.
Explanation:
The wire, the flagpole, and the ground make up the three sides of a triangle.
One angle of this triangle is given as
45
o
.
The angle of the flagpole with the ground must be
90
o
.
So the last angle must be
45
o
.
Because of the right angle
(
90
o
)
of the flagpole and the ground, this is a
right triangle
. The wire forms the hypotenuse.
Because both of the other angles are the same (both are
45
o
), this is an
isosceles
right triangle (the legs are equal.)
This particular kind of right triangle is called a
45
−
45
−
90
triangle, named for the degrees in its angles.
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.
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The measurements of these triangles are known by memorization:
The
45
−
45
−
90
isosceles right triangle has these properties:
It forms half a square, cut in half along the diagonal, so it is a
right triangle
.
This diagonal line forms the
hypotenuse
of the triangle.
The sides
s
(the legs) are the same as each other, so
it is an
isosceles right triangle.
The length of the hypotenuse is always
s
√
2
Here is a diagram of the
45
−
45
−
90
isosceles right triangle:
Explanation: