Question

find the length of the third side of the triangle by using the pythagorean theorem.
the third side is
20 cm
?
29 cm
cm long.

Explanation:

Step1: Apply Pythagorean theorem

$$a^{2}+b^{2}=c^{2}$$
Let \(a = 20\), \(c = 29\), find \(b\).

Step2: Rearrange formula

$$b^{2}=c^{2}-a^{2}$$
$$b^{2}=29^{2}-20^{2}$$

Step3: Calculate squares

$$29^{2}=841$$, $$20^{2}=400$$
$$b^{2}=841 - 400$$

Step4: Subtract

$$b^{2}=441$$

Step5: Take square root

$$b=\sqrt{441}$$
$$b = 21$$

Answer:

21