Answer:
4
Explanation:
This is an isosceles and right triangle at the same time
In fact, this triangle is called 45-45-90 special right triangle and the side lengths for this special triangle is as follows:
The sides that see the angle with measure 45 is represented with x
and
The side that sees the angle with measure 90 is represented with x
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one of the sides that has angle measure 45 is given as 4
to find the length of BC we we need to multiply 4
with
4
*
= 4