**Pythagoras is when you have a triangle and you know what the length of 2 of the sides. You then need to find out what the other side is. The triangle is ALWAYS a right angle triangle and the side opposite the right angle is called the Hypotenuse.**

**When working out the other side you normaly split the triangle into sections like above.**

**This is how you work out Pythagoras:**

Side A = 28cm

Side B = 21 cm

Side C = x (you work it out)

Side A = 28cm

Side B = 21 cm

Side C = x (you work it out)

**A + B = C**

A squared + B squared = C squared

A squared + B squared = C squared

**A = a squared = 28 squared = 784**

B = b squared = 21 squared = 441

C = 784 + 441 = 1225

x = 1225 square root

x = 35cm

B = b squared = 21 squared = 441

C = 784 + 441 = 1225

x = 1225 square root

x = 35cm

**EG1)**

Side A = 6cm

Side B = 10cm

Side C = x (find out the length of the Hypotenuse)

Side A = 6cm

Side B = 10cm

Side C = x (find out the length of the Hypotenuse)

**A + B = C**

A squared + B squared = C squared

A squared + B squared = C squared

**A = A squared = 6 squared = 36**

B = B squared = 10 squared = 100

C = 36 + 100 = 136

x = 136 square root

B = B squared = 10 squared = 100

C = 36 + 100 = 136

x = 136 square root

**x = 11.66190379......**

x = 11.7cm to 1 dp

x = 11.7cm to 1 dp

B = 7.5cm

__Question__

1. A = 4cmB = 7.5cm

**What is x ?**