Question

Proof that area of a parallelogram is base × altitude..

Answer 1

now area of parallelogram ABCD = area of triangle ADC + area of triangle CBA

ar. of parallelogram = 2 × area of ADC

because ar. of ADC = ar. of CBA

see in figure

ar of ADC = DC × AM÷2 = X × H ÷ 2

thus area of paralleogram = 2× X×H÷2

area of parallelogram =X×H