If the height and sum of parallel side of a trapezium are increase three times then find the change in area

If the length of three sides of a trapezium other than base are equal to 10cm, then find the area of trapezium when it is maximum.

If the lengths of the two parallel sides of a trapezium are 5 cm and 7 cm and the distance between these parallel sides is 4cm. Find its area (in cm^(2) ).

Parallel sides of a trapezium are 8cm and 6cm where as its altitude is 4m. Find the area of the trapezium.

If the lengths of the two parallel sides of a trapezium are 8 cm and 10 cm and the distance between these parallel sides is 6 cm. Find its area (in cm^(2) ).

A circle is inscribed in a trapezium in which one of the non-parallel sides is perpendicular to the two parallel sides. Then A) the diameter of the inscribed circle is the geometric mean of the lengths of the parallel sides B) the diameter of the inscribed circle is the harmonic mean of the lengths of the parallel sides C) the area of the trapezium is the area of the rectangle having lengths of its sides as the lengths of the parallel sides of the trapezium D) the area of the trapezium is half the area of the rectangle having lengths of its sides as the lengths of the parallel sides of the trapezium

The lengths of the parallel sides of a trapezium are in the ratio 5 :3 and the distance between them is 12 . 5 cm .If the area of the trapezium is 450cm^(2) , find the lengths of its parallel sides .