Answer:
18.3
18.3 only has three significant figures while the other numbers have more
X=80 because the square it cut in half so both triangles have the same measure in angles a square has to equal 180 the two measure Gaven are 80 and 20 which makes 100 .180-100=80
x=80
Cos 45 = √6 / y
√2 / 2 = √6 / y
Inverse both sides
2 / √2 = y / √6
Multiply both sides by √6
√6 × 2 / √2 = √6 × y / √6
√2 × √3 × 2 / √2 × 1 = y
<h2>y = 2√3</h2>
Answer: 
Step-by-step explanation:
multiply these -3/7 times by 3/8: Answer is -9/56
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This is true
Perpendicular lines = circumscribe
angle bisect = incircle
altitude = orthocenter
median = centriod