Question

please help me to solve these questions

Answer 1

Area of Trapezium = sum of parallel sides*altitude/2
 
26 = 6.5*altitude/2
 so, altitude  =  52/6.5 = 8 cm

Answer 2

$area \: of \: trapezium = \frac{1}{2} \times sum \: of \: parallel \: sides \times altitude \\ 26 = \frac{1}{2} \times 6.5 \times x \\x = \frac{26 \times 2}{6.5} \\ x = 8cm$