Question

. CDEF is a trapezium

Answer 1

9514 1404 393

Answer:

  24 cm²

Step-by-step explanation:

To find the area of the trapezium, we must know the length CD. That means we must know the length BC. Fortunately, the perimeter of ABCF is given, so we have ...

  P = 2(AB +BC)

  BC = (P/2) -AB = (20 cm)/2 - 6 cm = 4 cm

Then CD is ...

  CD = BD -BC = 9 cm -4 cm = 5 cm

The area of the trapezium is given by the formula ...

  A = (1/2)(b1 +b2)h

  A = (1/2)(5 cm + 3 cm)(6 cm) = 24 cm²

The area of trapezium CDEF is 24 cm².