Congruent means it has the same lengths and angles. So shapes that are exactly the same, perhaps just rotated so A, B, C and F
For the bottom questions, the octagon has sides of 7cm. An octagon has eight sides so the perimeter is 8 x 7 = 56 cm
b) the sides of the pentagon are given so just add them up (4 + 6 + 4 + 5 + 5 = 24 cm)
the same is true for d
for c and e you need to know some facts about these shapes (rectangle and parallelogram) ie that opposite sides of them are equal.
