What is the area of a triangle with a base of 8 cm and a height of 5 cm?

To find the area of a triangle, the formula used is:

[

\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}

]

In this case, the base is 8 cm and the height is 5 cm. Plugging in these values into the formula gives:

[

\text{Area} = \frac{1}{2} \times 8 , \text{cm} \times 5 , \text{cm}

]

Calculating this step-by-step:

1. First, multiply the base by the height:

(8 \times 5 = 40) cm².

2. Then, take half of that result:

(\frac{1}{2} \times 40 = 20) cm².

Thus, the area of the triangle is indeed 20 cm². This matching with the calculated area confirms that the first choice is accurate.