The perimeter of an equilateral triangle is 15 cm, the height is 3.5 cm, and its area is ()

The perimeter of an equilateral triangle is 15 cm, the height is 3.5 cm, and its area is ()

This is simple. The knowledge points used in this question are as follows:
(1) Perimeter of equilateral triangle = side length * 3
(2) Area of equilateral triangle = side length * height * 1 / 2
Side length of equilateral triangle: 15 / 3 = 5cm
Area of equilateral triangle: 5 * 3.5 = 17.5 square centimeter

The side length of square ABCD is 4, P is a point on DC, let DP = x, find the function relation of area y of triangle APD with respect to X and the value range of X

The functional relation of area y of triangle APD with respect to X is as follows:
Y=1/2*X*4=2X
The value range of X is: 0

As shown in the figure, the side length of square ABCD is 4, P is a point on DC. Let DP = X. (1) find the functional relation of area y of △ APD with respect to x, and write out the value range of independent variable x; (2) draw the image of this function

(1) S △ ADP = 12 · DP · ad = 12x × 4 = 2x, ｜ y = 2x, (0 ＜ x ≤ 4); (2) this function is a positive proportion function, and the image passes through (0, 0) (1, 2), because the independent variable has a value range, so the image is a line segment