Find the area of a quadrilateral `A B C D\ ` whose sides are `9\ m ,\ 40\ m ,\ 28\ m\ a n d\ 15\ m` respectively and the angle between the first two sides is a right angle.

Explanation

To find the area of the quadrilateral ABCD with sides 9 m, 40 m, 28 m, and 15 m, where the angle between the first two sides (AB and BC) is a right angle, we can follow these steps:

### Step 1: Identify the triangles in the quadrilateral
Since angle ABC is a right angle, we can divide the quadrilateral ABCD into two triangles: triangle ABC and triangle ACD.

### Step 2: Calculate the area of triangle ABC
The area of a right triangle can be calculated using the formula:
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