The height of a triangle is fixed, its area and the growth of its base___ Proportional relationship

The height of a triangle is fixed, its area and the growth of its base___ Proportional relationship

Because the area of the triangle is equal to the bottom × height △ 2, so the area of the triangle △ the length of the bottom = 12 high (certain), which is in line with the meaning of positive proportion, so the height of the triangle is certain, and its area is in direct proportion to the length of the bottom, so the answer is: positive

The height of a triangle is fixed, its area and the growth of its base___ Proportional relationship

Because the area of the triangle is equal to the bottom × height △ 2, so the area of the triangle △ the length of the bottom = 12 high (certain), which is in line with the meaning of positive proportion, so the height of the triangle is certain, and its area is in direct proportion to the length of the bottom, so the answer is: positive

As shown in the trapezoid, the shadow area is 150 square centimeter, calculate the trapezoid area

The height of triangle is: 150 × 2 △ 15, = 300 △ 15, = 20 (CM); the area of trapezoid is: (15 + 25) × 20 △ 2 = 40 × 20 △ 2, = 800 △ 2, = 400 (CM); a: the area of trapezoid is 400 square cm