Rectangle Side Ratio Problem: Finding Length m Using sqrt(x/2)

Question

The rectangle ABCD is shown below.

AB = X

The ratio between AB and BC is x2 \sqrt{\frac{x}{2}} .


The length of diagonal AC is labelled m.

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Determine the value of m:

Video Solution

Solution Steps

00:00 Mark the correct statement
00:03 Let's mark the side with X according to the given data
00:07 We'll substitute this value in the given ratio and solve for BC
00:17 Multiply by the reciprocal
00:22 Isolate BC
00:30 Divide X by twice the factor of square root X
00:34 Simplify what we can
00:39 This is the length of side BC
00:50 Let's use the Pythagorean theorem in triangle ABC
00:57 Substitute appropriate values and solve
01:16 Add 1 to match our statement
01:33 Use the distributive law
01:36 And this is the solution to the question

Step-by-Step Solution

We know that:

ABBC=x2 \frac{AB}{BC}=\sqrt{\frac{x}{2}}

We also know that AB equals X.

First, we will substitute the given data into the formula accordingly:

xBC=x2 \frac{x}{BC}=\frac{\sqrt{x}}{\sqrt{2}}

x2=BCx x\sqrt{2}=BC\sqrt{x}

x2x=BC \frac{x\sqrt{2}}{\sqrt{x}}=BC

x×x×2x=BC \frac{\sqrt{x}\times\sqrt{x}\times\sqrt{2}}{\sqrt{x}}=BC

x×2=BC \sqrt{x}\times\sqrt{2}=BC

Now let's look at triangle ABC and use the Pythagorean theorem:

AB2+BC2=AC2 AB^2+BC^2=AC^2

We substitute in our known values:

x2+(x×2)2=m2 x^2+(\sqrt{x}\times\sqrt{2})^2=m^2

x2+x×2=m2 x^2+x\times2=m^2

Finally, we will add 1 to both sides:

x2+2x+1=m2+1 x^2+2x+1=m^2+1

(x+1)2=m2+1 (x+1)^2=m^2+1

Answer

m2+1=(x+1)2 m^2+1=(x+1)^2