Question

ive never seen a question like this tbh

Answer 1

The formula A=1/2bh is used to find the area of a triangle. You can find from the diagram that the base of this triangle is 9cm, and the height is 4cm. Plug those numbers into the area of a triangle formula.

A=1/2(9)(4)

Multiply to get 18 square cm, which is choice D.

Answer 2

Easiest question I have ever seen! :)
We know the formula of the area of a triangle
  =$\frac{1}{2}$×base×height
 The height given is 4 cm (we should take the perpendicular height)
  And the base length is 8 cm
Simply, we just substitute the given numbers
  =$\frac{1}{2}$×8×4
  =18 cm²
The answer is D: 18 square m