# 45-45-90 Triangle

See how to solve a 45-45-90 triangle.

2 examples and their solutions.

## 45-45-90 Triangle

### Definition, Property

whose interior angles are 45º, 45º, and 90º.

The ratio of the sides is

1 : 1 : √2.

So a 45-45-90 triangle is

an isosceles right triangle.

### Example

[1]

45°, 90°

→ This is a 45-45-90 triangle.

→ Top angle: 45°

→ This is a 45-45-90 triangle.

→ Top angle: 45°

↓

x = 7

[2]

45-45-90 triangle is an isosceles triangle.

→ x = 7

→ x = 7

Close

### Example

x√2 = 111 - [2]

x√2 = 11

x = 11√2

[1]

Isosceles right triangle

→ This is a 45-45-90 triangle.

→ Draw a (1, 1, √2) triangle.

→ This is a 45-45-90 triangle.

→ Draw a (1, 1, √2) triangle.

[2]

Close