Free. Exclusive. Just for you.
Four unique services that make learning easier, faster, and smarter - only on our website.

Practice worksheet for calculating missing side lengths in right triangles using the Pythagorean theorem.

Worksheet titled "Finding Missing Side Lengths in Right Triangles" with six right triangles, each labeled with two side lengths and one unknown side marked as 'x', requiring use of the Pythagorean theorem to solve.

Worksheet titled "Finding Missing Side Lengths in Right Triangles" with six right triangles, each labeled with two side lengths and one unknown side marked as 'x', requiring use of the Pythagorean theorem to solve.

PNG 405×574 13.8 KB Free · Personal Use
Quality Assured by Worksheets Library Team
Reviewed for educational accuracy and age-appropriateness
ID: #307370
Show Answer Key & Explanations Step-by-step solution for: Unknown Side Lengths in Right Triangles Worksheets
To solve the missing side lengths in each right triangle using the Pythagorean theorem, we use the formula:

\[
a^2 + b^2 = c^2
\]

where:
- \( a \) and \( b \) are the legs of the right triangle,
- \( c \) is the hypotenuse (the longest side).

Let's solve each problem step by step.

---

1)


Given:
- One leg = 12 yd
- Hypotenuse = 15 yd
- Missing side = \( x \)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
x^2 + 12^2 = 15^2
\]
\[
x^2 + 144 = 225
\]
Subtract 144 from both sides:
\[
x^2 = 81
\]
Take the square root of both sides:
\[
x = \sqrt{81} = 9
\]

Answer:
\[
x = 9 \text{ yd}
\]

---

2)


Given:
- One leg = 16 in
- Hypotenuse = 20 in
- Missing side = \( x \)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
x^2 + 16^2 = 20^2
\]
\[
x^2 + 256 = 400
\]
Subtract 256 from both sides:
\[
x^2 = 144
\]
Take the square root of both sides:
\[
x = \sqrt{144} = 12
\]

Answer:
\[
x = 12 \text{ in}
\]

---

3)


Given:
- One leg = 5 ft
- Other leg = 12 ft
- Missing side = \( x \) (hypotenuse)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
5^2 + 12^2 = x^2
\]
\[
25 + 144 = x^2
\]
\[
169 = x^2
\]
Take the square root of both sides:
\[
x = \sqrt{169} = 13
\]

Answer:
\[
x = 13 \text{ ft}
\]

---

4)


Given:
- One leg = 8 yd
- Hypotenuse = 10 yd
- Missing side = \( x \)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
x^2 + 8^2 = 10^2
\]
\[
x^2 + 64 = 100
\]
Subtract 64 from both sides:
\[
x^2 = 36
\]
Take the square root of both sides:
\[
x = \sqrt{36} = 6
\]

Answer:
\[
x = 6 \text{ yd}
\]

---

5)


Given:
- One leg = 18 in
- Hypotenuse = 30 in
- Missing side = \( x \)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
x^2 + 18^2 = 30^2
\]
\[
x^2 + 324 = 900
\]
Subtract 324 from both sides:
\[
x^2 = 576
\]
Take the square root of both sides:
\[
x = \sqrt{576} = 24
\]

Answer:
\[
x = 24 \text{ in}
\]

---

6)


Given:
- One leg = 36 ft
- Hypotenuse = 65 ft
- Missing side = \( x \)

Using the Pythagorean theorem:
\[
a^2 + b^2 = c^2
\]
\[
x^2 + 36^2 = 65^2
\]
\[
x^2 + 1296 = 4225
\]
Subtract 1296 from both sides:
\[
x^2 = 2929
\]
Take the square root of both sides:
\[
x = \sqrt{2929} = 54
\]

Answer:
\[
x = 54 \text{ ft}
\]

---

Final Answers:


\[
\boxed{9, 12, 13, 6, 24, 54}
\]
Parent Tip: Review the logic above to help your child master the concept of is it a right triangle worksheet.
Print Download

How to use

Click Print to open a print-ready version directly in your browser, or use Download to save the file to your device. The ⭐ Answer button generates an AI answer key instantly - useful for teachers who need a quick reference. Need a different version? Our AI Worksheet Generator lets you create a custom worksheet on any topic in seconds.

(view all is it a right triangle worksheet)

Right Triangle Trig Worksheet
RIGHT TRIANGLE AREA 3 ANSWERS | Triangle worksheet, Area and ...
Using Special Right Triangles Worksheet | PDF Printable Geometry ...
Special Right Triangles Worksheet for 9th - 12th Grade | Lesson Planet
4-Right Triangle Congruence.pdf - Kuta Software
Calculating the Area and Height of Right Triangles (A)
Area of Right Triangle Worksheets
Identifying Right Triangles Worksheet Download
Calculating Angles of a Right-Angled Triangle Worksheet / Worksheet
Area of Right Angled Triangles Worksheet | Fun and Engaging PDF ...