PSAT: Questions

The correct answer is (D).

The correct answer is (D).

Did you recognize the triangle as a

45

°

-

45

°

-

90

°

triangle,

which has sides in the ratio of 1:1:

√ 2

? If you did, you could

use that ratio to determine what

x

is.

First you want to determine a multiplier to use to convert our

1:1:

√ 2

triangle to our example triangle - in other words, what

must you multiply 1 by to get

√ 2

? The answer is

√ 2

So for x, we can multiply

√ 2

from our standard

45

°

45

°

90

°

triangle, by our multiplier:

√ 2

√ 2

×

√ 2

=

2

a2

+

b2

=

c2

√ 2

squared

+

√ 2

squared

=

c2

2

+

2

=

c2

4

=

c2

2

=

c

You can also solve this using the Pythagorean Theorem since it is has a 90 degree angle.The correct answer is 2.