Question

14. The base of a parallelogram is twice its height. If
its area is 800 cm?, find its height and base.
the
(Hint - Take height = x, base =
2x, area=2xxx
= 800)
800
> x = 400 cm² = x=20
x2 =
or
2.
han​

Answer 1

Correct Question:

The base of a parallelogram is twice its height. If its area is 800 cm², find its height and base.

Required Solution:

Given:

• The base of a parallelogram is twice its height.
• Its area is 800 cm².

To calculate:

• Height and base

Calculation:

Let the height of the parallelogram be x cm.Therefor,its base becomes 2x cm.

We know that,

• Area of parallelogram = length × breadth

According to the question:

→ 800 = (x) × (2x)

→ 800 = 2x²

→ x² = $\dfrac{800}{2}$

→ x² = 400

→ x = $\sqrt{400}$

→ x = 20 cm [Height]

• Height = x = 20cm

• Base = 2x = (2×20) = 40cm

▬▬▬▬▬▬▬▬▬▬▬

Extra!!

Perimeter:

• Perimeter of square : 4 × side
• Perimeter of rectangle : 2 ( l + b )
• Perimeter of parallelogram : 2 ( l + b )
• Perimeter of rhombus : 4 × side
• Perimeter of trapezium : Sum of sides
• Perimeter of triangle : Sum of sides
• Perimeter of circle (circumference) : 2πr

Area:

• Area of square : (Side)²
• Area of rectangle : l × b
• Area of parallelogram : Base × height
• Area of rhombus : ½ × diagonal$\sf {_1}$ × diagonal$\sf {_2}$
• Area of trapezium : ½ × (sum of parallel sides) × h
• Area of triangle : ½bh
• Area of circle : πr²

▬▬▬▬▬▬▬▬▬▬▬

Answer 2

Let the height = h

⇒ base = b = 2 × h

Area = 800 cm²

We know, area of ||gm = b × h {Base × Height}

According to the question:-

b × h = 800

⇒ 2h × h = 800

⇒ h² = 400

⇒ h = √(400) = √[(20)²] = 20 cm

Similarly,

Base = 2h = 20 cm × 2 = 40 cm