If you have the width and height of a triangle how do you get the third length?

Really you don't have enough data to calculate this.

The height is not necessarily one of the three sides. The height is perpendicular to the width.

If the triangle has a right angle, and you know two of the sides, you can calculate the third side using the rule of Pythagoras (a squared + b squared = c squared).

Really you don't have enough data to calculate this.

The height is not necessarily one of the three sides. The height is perpendicular to the width.

If the triangle has a right angle, and you know two of the sides, you can calculate the third side using the rule of Pythagoras (a squared + b squared = c squared).

Really you don't have enough data to calculate this.

The height is not necessarily one of the three sides. The height is perpendicular to the width.

If the triangle has a right angle, and you know two of the sides, you can calculate the third side using the rule of Pythagoras (a squared + b squared = c squared).

Really you don't have enough data to calculate this.

The height is not necessarily one of the three sides. The height is perpendicular to the width.

If the triangle has a right angle, and you know two of the sides, you can calculate the third side using the rule of Pythagoras (a squared + b squared = c squared).