The rectangle isblocked by a Triangle As shown below Determine the area in grey in terms of rectangle’s How in the image by drawing a single line that helps to know the answer at a glance?
If you drop a perpendicular line from the top vertex of the triangle, you will immediately understand that the width of the rectangle is the same as the height of the triangle... Any triangle drawn in between 2 parallel lines with a common base has the same area, and is half the area of any parallelogram with the same base and height... Area of triangle is 1/2 of base X height, Area of rectangle is base X height Therefore, the area of the triangle is exactly half of the area of the rectangle and so, the area of the shaded portion is the other half of area of the rectangle. Keep smiling HR
So it is not a challenge but sheer elementary. Thank you @hrastro . Thanks also to @Anisu for liking it indicating that you too are passionate about maths. Regards.