MODERATE EXERCISES

(1) The length of a side of an equilateral 
triangle is 80 cm.

 (a) Find the height of the triangle.

 (b) Find the area of the triangle.

 (c) If the triangle were being constructed out of fabric costing $2 per 
     square meter, how much would it cost to make the triangle?

 

 (a)  802 = 402 + x2
      6400 = 1600 + x2
      4800 = x2

       x = 40

 (b)  Area = (80)(40)/2
           = 1600 cm2
           = 0.16 m2

 (c)  Total cost = (2)(0.16)
                 = 0.32
                 = $0.55