1. **Problem Statement:**
You are given rectangle ADCB with area 108 cm², side BA = 6 cm, and DC = ED. You need to find:
- Length of rectangle ADCB (side AD)
- Area of triangle ADC
- Area of shaded triangle AEC
2. **Step 1: Find length AD of rectangle ADCB**
- Recall the area formula for a rectangle: $$\text{Area} = \text{length} \times \text{width}$$
- Here, width BA = 6 cm, area = 108 cm²
- Use formula: $$108 = AD \times 6$$
- Solve for AD by dividing both sides by 6:
$$AD = \frac{108}{6}$$
- Simplify the fraction by canceling common factors:
$$AD = \frac{\cancel{108}}{\cancel{6}} = 18$$
3. **Step 2: Find area of triangle ADC**
- Triangle ADC is formed by diagonal AC of rectangle ADCB
- Area of triangle = half the area of rectangle because diagonal divides rectangle into two equal triangles
- Use formula:
$$\text{Area of } \triangle ADC = \frac{1}{2} \times \text{Area of rectangle}$$
- Substitute values:
$$= \frac{1}{2} \times 108$$
- Simplify:
$$= 54$$
4. **Step 3: Find area of shaded triangle AEC**
- Point E lies on AD such that DC = ED
- Use properties of rectangle and triangle area formulas
- Express length ED in terms of AD and use it to find length AE
- Use formula for area of triangle:
$$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$$
- Identify base and height for triangle AEC
- Calculate area using lengths found
This step-by-step approach will help you solve each part without directly giving the final answers. Try applying these steps carefully.
Rectangle Triangle Areas B7A0F2
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