This expression is already simplified.
The answer is D because there is one of the 0 and one of the 9
Holy @$#% THAT LOOKS HARD! Sorry, I can't help I don't know that math yet.
The triangle shown is a right triangle shown by the little square inside of it.
Area of a triangle is 1/2 x height x base
Rotating the shown triangle so the square is at a bottom corner the height is 6 and the base is 6
Area = 1/2 x 6 x 6 = 18 square cm
