Respuesta :

Answer:

26 cm

Step-by-step explanation:

The area of a trapezium is

A = 1/2 (b1+b2)*h  where b1 and b2 are the lengths of the bases

910 = 1/2 ( 21+49) h

910 = 1/2 (70)h

910 = 35h

Divide by 35

910/35 = 35h/35

26 = h