Area = \(\frac12 \times 10 \times 24 = 120\) cm² - Parker Core Knowledge

Understanding the Context

Given:
\[
\ ext{Area} = \frac{1}{2} \ imes 10 \ imes 24 = 120 \ ext{ cm}^2
\]

What Does This Formula Represent?

At first glance, the formula \(\frac{1}{2} \ imes \ ext{base} \ imes \ ext{height}\) seems unusual for standard rectangle area calculations. However, this expression often appears in specialized geometric contexts — for instance, when dealing with triangles, where the area is typically given by:

\[
\ ext{Area of a triangle} = \frac{1}{2} \ imes \ ext{base} \ imes \ ext{height}
\]

Key Insights

But in our example, the formula incorporates a factor of \(\frac{1}{2}\) multiplied by 10 and 24 — suggesting the shape might not be a regular rectangle but something derived from it, such as half of a triangle’s area or part of a composite figure.

Breaking Down the Calculation

Let’s analyze the given expression:

\[
\frac{1}{2} \ imes 10 \ imes 24 = 120 \ ext{ cm}^2
\]

Final Thoughts

• Base = 10 cm
  - Height = 24 cm
  - Multiply base and height: \(10 \ imes 24 = 240\)
  - Apply the \(\frac{1}{2}\) factor: \(\frac{1}{2} \ imes 240 = 120\) cm²

This implies either:
- The figure is a triangle with base 10 cm and height 24 cm, yielding area 120 cm²; or
- The calculation represents half the area of such a triangle, or uses a modified geometric model involving halved dimensions or projected surface areas.

Why 120 cm² Matters

The number 120 cm² appears frequently in real-world applications such as:

• Calculating fabric or material requirements in sewing and tailoring
  - Estimating display board areas for presentation boards
  - Determining land plots or floor space in architecture
  - Educational contexts for reinforcing multiplication and area formulas