A piece of iron sheet is 3 meters long and 2.34 meters wide. How many triangle traffic signs can be made with it, 9 decimeters at the bottom and 7.8 decimeters at the height? (splicing is not allowed)

A piece of iron sheet is 3 meters long and 2.34 meters wide. How many triangle traffic signs can be made with it, 9 decimeters at the bottom and 7.8 decimeters at the height? (splicing is not allowed)

The width of the triangle is just three times the height of the traffic sign. You can cut three
The length is more than three times of the triangle bottom, and the maximum height of the remaining material is 7.5
If splicing is not allowed, only 3 * 5 = 15 pieces can be cut first

The trapezoid is divided into two triangles A and B. the area difference between the two triangles is 32.4 square centimeters. The upper bottom of the trapezoid is 8 centimeters, and the lower bottom is 14 centimeters

Let the height be x, then 1 / 2 * 14 * X-1 / 2 * 8 * x = 32.4, and x = 10.8 (CM)
According to the trapezoidal area formula: trapezoidal area = (upper bottom + lower bottom) * height / 2,
S = (8 + 14) * 10.8 / 2 = 118.8 (cm2)

In the trapezoid below, cut off the largest triangle. What's the remaining area? It's 5cm high, 6cm at the top and 8cm at the bottom

5 × 6 △ 2 = 15 (square centimeter)