Question

1 by 2 x 60cm x H = 420cm

Answer 1

$find \: h \: = = > \frac{1}{2} \times 60 \times h = 420cm \\ \\ = > 30 \times h = 420cm \\ \\ = > h = \frac{420}{30} cm \\ \\ = > h = 14 \: \: \: ans.$