Trapezoid

 

The formula for the area of a trapezoid is A=1/2h(b1+b2) if teh area of the trapezoid is 847 square centimeters and it's height is 60.5 centimeters. Which of the following could be the length of one of the bases?     

 

A  26 cm        B  29 cm        C  32 cm        D  35 cm     

 

Area  =  (¹/₂) • h • (b₁ + b₂)     

  847  =  (¹/₂) • 60.5 • (b₁ + b₂)     

  847  =  (30.25) • (b₁ + b₂)     

 

(b₁ + b₂)  =  847 / (30.25)     

(b₁ + b₂)  =  28     

The answer has to be A because     

all the other answers are too large     

to add the other base to.     

 

check answer     

 

Area  =  (¹/₂) • h • (b₁ + b₂)     

          =  (¹/₂) • 60.5 • (26 + 2)     

          =  (¹/₂) • 60.5 • (28)     

          =  847   True     

   _.