Making road signs

This task is about working out area.
The figure below shows an AA sign just outside a school.
Anna measured the sign as a school project, and put her measurements on the drawing.
Children-crossing-sign.png

Question 2Change answer

a)  What is the length of the black line running around the edge of the rectangular sign saying 
     CHILDREN?

Question 2Change answer

b)  What is the area of sheet metal required to make the CHILDREN sign?

Question 2Change answer

c)  What is the area of sheet metal required to make the upper diamond-shaped sign?
     (a square of side 65 cm, turned through 45 degrees).

Question

d)  Sarah measured the height of the diamond-shaped sign as 92 cm (see the vertical line).
     She said she could work out the area from just this measurement.
     Anna said she would need more measurements to get the area.
     Who do you think is correct? 
 
 

    • Sarah

    • Anna

Explain your reasons.