# Hard SAT Math Question 94 — Video Explanation | 1600.now

Source: https://1600.now/hard/94

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94

A circle is inscribed inside of a square $ABCD$. If the square's diagonal has a length of $40$ cm, what is the radius of the circle, in cm?

A

$\frac{20\sqrt{2}}{2}$

B

$20$

C

$20\sqrt{2}$

D

$40\sqrt{2}$