Trapezoid area with sides 1.41,1.89,0.86,0.53 equal to 0.78
where a and b are bases, h is height
where m is the middle line, h is the height
where d1,d2 are diagonals, α° is the angle between them
A trapezoid is a quadrilateral whose two sides are parallel (bases) and the other two are not parallel (sides).
Trapezoid area formula 
where a and b are the bases, c and d are the sides
where r is the radius of the inscribed circle, α° is the angle between the base and the sideSolution:
S =
a+b
2
·
√c2 - ()2
(b-a)2+c2-d2
2·(b-a)
=
1.41+1.89
2
·
√0.862 - ()2
(1.89-1.41)2+0.862-0.532
2·(1.89-1.41)
=
3.3
2
·
√0.862 - ()2
0.482+0.862-0.532
2·0.48
=
3.3
2
·
√0.7396 - ()2
0.2304+0.7396-0.2809
0.96
= 1.65
·
√0.7396 - ()2
0.6891
0.96
= 1.65
·
√0.7396 - 0.7182
= 1.65
·
√0.7396 - 0.515524
= 1.65
·
√0.224076
= 1.65
·
0.473
=
0.78
Answer: trapezoid area with sides 1.41,1.89,0.86,0.53 equal to 0.78