Question 1 - Figure it out - Page 160 - Chapter 7 Class 8 - Area (Ganita Prakash II)

Transcript

Question 1 Find the area of the quadrilateral ABCD given that AC = 22 cm, BM = 3 cm, DN = 3 cm, BM is perpendicular to AC, and DN is perpendicular to AC.Quadrilateral ABCD is divided into two triangles ∆ ADC & ∆ ABC So, we can write Area of Quadrilateral ABCD = Area ∆ ADC + Area ∆ ABC Finding Area Separately Area ∆ ADC Now, Base = AC = 22 cm Height = AN = 3 cm Thus, Area of ∆ ADC = 1/2 × Base × Height = 𝟏/𝟐 × AC × AN = 1/2 × 22 × 3 = 11 × 3 = 33 cm2 Area ∆ ABC Now, Base = AC = 22 cm Height = BM = 3 cm Thus, Area of ∆ ABC = 1/2 × Base × Height = 𝟏/𝟐 × AC × AN = 1/2 × 22 × 3 = 11 × 3 = 33 cm2 Now, Area of Quadrilateral ABCD = Area ∆ ADC + Area ∆ ABC = 33 + 33 = 66 cm2