Answer:
27.5cm^2
Step-by-step explanation:
you can cut the triangle to make two right triangles
so 11 is the height and the width is 2.5 since your cutting the triangle in half
so 11x2.5=27.5 since its a right triangle you have to divide by two 27.5/2=13.75
that's the answer for one of the triangles now multiply it by two since you need the two right triangle to make the other triangle so the answer is 27.5
