Answer:
dissect the trapezium into a square and triangle. since the triangle is a right angled one the base is 17-7=10cm
the height is found using Pythagorean theorem to be 24cm i.e 26²=x²+10²,x=√(676-100),x=√576,x=24cn
area of trapezium is (1/2)(a+b)h
a is the shorter side and b the longer side
(1/2)*(7+17)24
=288cm²