Question

answer this question please !!!! ​

Answer 1

Answer:

Concept

~Here the concept of area of triangles is used.

The height is given as 3 cm and the area is given as 21cm². We have to find the base of the triangle . If we apply the formula of area of triangle we will get the value of the base.

-----------------------------------------------------

Formula used

$\bold \red{Area \: of \: triangle = \frac{1}{2}×B×H}$

where

• B denotes Base
• H denotes height

-----------------------------------------------------

Solution

Let us assume the base of the triangle as B

$\sf{ \implies \:area\:of\: triangle = \frac{1}{2}×B×H} \\ \\ \sf{ \implies \: 21 = \frac{1}{2}×B×3}\\ \\ \sf{\implies 21=\frac{3B}{2}}\\ \\ \sf{ \implies B= \frac{21×2}{3}} \\ \\ \sf{\implies \color{lightgreen} B= 14 cm}$

Therefore the base of triangle is 14cm.

-----------------------------------------------------

More to know !!

➜The perimeter of a square = 4 × side

➜Perimeter of rectangle = 2 × (l + b)

➜Area of a square = side × side

➜Area of a rectangle = l × b

➜Circumference of a circle = πd

➜Area of circle= 2πr²

-----------------------------------------------------

Answer 2

Let the base be = (x) cm

We know, area of triangle = ½ bh

∴ Area = ½ (3 cm)(x)

As per condition,

⇒ 3/2 x = 21

⇒ x = 42/3

⇒ x = 14

So, base is of 14 cm.