Question

The area of a triangle is 20cm². The height is 5cm. What is the base? A.4cm B.8cm C. 10cm D.5cm​

Answer 1

Area = 20cm

5cmx4cm= 20cm

B =20cm

Answer 2

`b= 8cm`

Explanation:

Let's refer to the formula of the area of triangles:

`A=(b*h)/(2)`, where b is the legth of the base of the triangle, and h is its height.

Now, let's solve the question.

1. Solve the area of triangle formula for b (base).

We need to find the base of this triangle, therefore, let's adequate the area formula for the case.

`A=(b*h)/(2)`

a. Multiply both sides by 2 and cancel.

`2A=(b*h)/(2)*2\\ \\2A=b*h`

b. Divide both sides by "h" and cancel.

`(2A)/(h) =(b*h)/(h)\\ \\(2A)/(h) =b`

c. Reorganize.

`b=(2A)/(h)`

2. Substitute the values in the new expression and calculate.

`b=(2A)/(h)\\ \\b=(2(20cm^(2) ))/(5cm)\\ \\b=(40cm^(2) )/(5cm)\\ \\b= 8 cm`

3. Express your result.

`b= 8cm`

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Check out the solving to find the expression for b made manually in the image attached below, in case you didn't understand it through the digital expressions.