A triangular flag has a height of 15 inches and a base length of 25 inches. Magnolia makes a scale drawing of the flag in which the base length is 10 inches. What is the area of Magnolia’s scale drawing? Solve the problem by computing the actual area from the scale drawing. Show your work.(4 points) [simple and for 7th grade]

1 answer

To find the area of Magnolia's scale drawing of the triangular flag, we can first calculate the area of the actual flag and then find the area of the scaled-down version.

Step 1: Calculate the area of the actual flag.

The area \(A\) of a triangle can be calculated using the formula:

\[ A = \frac{1}{2} \times \text{base} \times \text{height} \]

In this case, the base of the actual flag is 25 inches and the height is 15 inches.

Substituting in the values:

\[ A = \frac{1}{2} \times 25 \times 15 \]

Step 2: Perform the multiplication.

Calculate \(25 \times 15\):

\[ 25 \times 15 = 375 \]

Now substitute that value back into the area formula:

\[ A = \frac{1}{2} \times 375 = \frac{375}{2} = 187.5 \]

So, the area of the actual flag is 187.5 square inches.

Step 3: Find the scale factor.

Magnolia's scale drawing has a base length of 10 inches. To find the scale factor, we compare the base lengths:

\[ \text{Scale factor} = \frac{\text{base of scale drawing}}{\text{base of actual flag}} = \frac{10}{25} = \frac{2}{5} \]

Step 4: Calculate the area of the scale drawing.

Since the area scales with the square of the scale factor, we need to square the scale factor:

\[ \text{Scale factor for area} = \left(\frac{2}{5}\right)^2 = \frac{4}{25} \]

Now, we can find the area of the scale drawing:

\[ \text{Area of scale drawing} = \text{Area of actual flag} \times \frac{4}{25} \]

Substituting the area of the actual flag:

\[ \text{Area of scale drawing} = 187.5 \times \frac{4}{25} \]

Step 5: Perform the multiplication for the area of the scale drawing.

Calculating \(187.5 \times \frac{4}{25}\):

To simplify, first find the value of \(187.5 \div 25\):

\[ 187.5 \div 25 = 7.5 \]

Now multiply this by 4:

\[ 7.5 \times 4 = 30 \]

Therefore, the area of Magnolia’s scale drawing is 30 square inches.

\[ \text{Final answer: } 30 \text{ square inches} \]