Question

Observe the given rectangle and calculate the following:
i. perimeter of ABCD
ii . area of BCD.​

Answer 1

Answer:

Here's your answer. Hope it helps you.

Answer 2

(I)

• given that perimeter of ABCD
• we konw that
• perimeter is equal to sum of all sides
• perimeter of ABCD=2(l+b)
• lenght (l) is 20 cm
• breadth (b) is 15 cm
• perimeter of ABCD=2(20+15)
• Perimeter of ABCD = 2(35)= 70
• so,perimeter is 70 cm

(ii)

• area of BCD is triangle so
• area of trinagle = bh/2
• breadh (b) is 20 cm
• height we have to findout by using method pythagorens
• (25)^2 =(20)^2 +(x)^2
• 625 = 400 +(x)^2
• (x)^2= 625-400
• (x)^2= 225
• (x)=√225
• (x) =15 cm
• so,the height is 15 cm
• area of triangle is bh/2
• area of triangle = 20 ×15/2
• area of triangle = 150 cm^2