Question

Find the length of the unknown side.
25 cm
15 cm

Answer 1

b = 20 cm.

Explanation:

Define and explain:

This is a right triangle, so the Pythagorean Theorem applies.

The Pythagorean Theorem states that the sum of the squared legs will equal the squared length of the hypotenuse.

The legs of a triangle are the sides that form the right angle.

The hypotenuse is the longest side; the hypotenuse is always diagonal from the small square indicating a right angle.

Solve:

`a^2+b^2=c^2`

`a,b-legs`

`c-hypotenuse`

`15^2+b^2=25^2`

`225+b^2=625`

`625-225=400`

`b^2=400`

`b=20`

Conclude:

Therefore, the length of the unknown side is 20 centimeters.