An isosceles trapezoid has bases of length 20 and 12 centimeters and legs of length 11 centimeters what is the area of the trapezoid to the nearest tenth

Answer 1

From the Pythagorean theorem,
h=sqrt(c^2-1/4(b-a)^2),
(1)

so
A = 1/2(a+b)h
(2)
= 1/2(a+b)sqrt(c^2-1/4(b-a)^2).
copied and pasted from Googleing Isosceles Trapezoid and clicking on the 2nd one, Wolfram Math World. sqrt is how the square root symbols pasted in. So if you need more detail, go there, they rock!