Area and perimeter of four shapes

This task is about finding the shape with the largest area and longest perimeter.
Shapes A to D are made up of identical equilateral triangles.
The three sides of each triangle are each 1 cm long.
 
shape A made using triangles
Shape A
 
shape B made using triangles
Shape B
 
shape C made using triangles
Shape C
shape D made using triangles
Shape D
 

Question

a)  Which of the shapes has the largest area?

    • shapeA.png

    • shapeB.png

    • shapeC.png

    • shapeD.png

    • All the shapes have the same area

Question

b)  Which of the shapes has the longest perimeter?

    • shapeA.png

    • shapeB.png

    • shapeC.png

    • shapeD.png

    • All the shapes have the same perimeter