Question

1. the expression \\( \frac { 1 } { 2 } a ( b + c ) \\) can be used to find the area of the trapezoid. what is the area of the trapezoid when \\( a = 5.5 \\), \\( b = 5 \\), and \\( c = 7.2 \\)? (example 4)

Explanation:

Step1: Substitute the values into the formula

Substitute \(a = 5.5\), \(b = 5\), and \(c = 7.2\) into the formula \(\frac{1}{2}a(b + c)\).

$$ \frac{1}{2}\times5.5\times(5 + 7.2) $$

Step2: Calculate the sum inside the parentheses

First, calculate \(5+7.2\).

$$ 5 + 7.2=12.2 $$

Step3: Multiply the numbers

Now, calculate \(\frac{1}{2}\times5.5\times12.2\).

$$ \frac{1}{2}\times5.5\times12.2 = 2.75\times12.2 $$

$$ 2.75\times12.2=(2 + 0.75)\times12.2=2\times12.2+0.75\times12.2 $$

$$ 2\times12.2 = 24.4 $$

$$ 0.75\times12.2=\frac{3}{4}\times12.2 = 9.15 $$

$$ 24.4+9.15 = 33.55 $$

Answer:

\(33.55\)