# Basic Geometry : How to find the perimeter of a 45/45/90 right isosceles triangle

## Example Questions

### Example Question #1121 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1121 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1123 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1124 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1125 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1126 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1127 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1131 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1132 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.

### Example Question #1133 : Basic Geometry

Find the perimeter.

Explanation:

Notice that the given triangle is a right isosceles triangle. The two legs with the tick marks are the same length.

The lengths of the legs in the given triangle are then .

Next, find the length of the hypotenuse by using the Pythagorean Theorem.

Plug in the value of the length of a leg to find the length of the hypotenuse.

Finally, recall how to find the perimeter of a triangle:

Plug in the values for this triangle to find its perimeter.

Make sure to round to two places after the decimal.