McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
6. Inequalities in Two Triangles
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Exercise 46 Page 462

B

Practice makes perfect

Two sides of a square and a diagonal form a right triangle.

Recall that the Pythagorean Theorem states that in a right triangle the square of the length of the hypotenuse is the sum of the square of the length of the legs. We can use this to express the length of the diagonal of a square in terms of the length of the sides.
a^2+a^2=d^2
â–Ľ
Solve for d
2a^2=d^2
d^2=2a^2
d=sqrt(2a^2)
d=sqrt(2)sqrt(a^2)
d=sqrt(2)a
It is given that a=x+3, let's substitute this in the expression we found.
d=sqrt(2)a
d=sqrt(2)( x+3)
d=sqrt(2)x+sqrt(2)* 3
d=xsqrt(2)+3sqrt(2)
The correct answer is B.