How about colored steel tile?

Suppose the roof is a right-angled trapezoid with an upper bottom of 24m and a lower bottom of10.5m, and the height is unknown.

According to Pythagorean theorem, we can know that:

Height 2 = hypotenuse 2- base 2

The hypotenuse is 24m and the base is 10.5m, so:

Height 2 = 24 2-10.52 = 414.75.

Height ≈ 20.36m.

Therefore, the roof area is:

(Upper bottom+Lower bottom) × Height ÷ 2

=(24 + 10.5)× 20.36 ÷ 2

Material 357.92 square meters

Therefore, about 357.92 square meters of colored steel tiles are needed.