1. Fill in the blanks: (28 points)
Name:
Score:
① 35,000 square meters = (
) hectares
3.25 hours = () (
) points
3 m 5 cm = (
) meter
500 square kilometers = (
) hectares
② There is a right-angled triangular plot with an area of 300 square meters, one right-angled side is 125m, and the other right-angled side is (
) meters.
(3) Two identical trapezoids can be merged into one (
), if the area of the mosaic pattern is 4.8 square decimeters, then the area of the trapezoid is (
) Square decimeter.
(4) The sum of the upper and lower bottoms of the trapezoid is 18 decimeter, which is three times higher, and its area is (
)。
⑤ The area of a triangle is 10 square meter. If the bottom and height are tripled, its area is (
) square meters.
⑥ The channel section is trapezoidal, with a mouth width of 1.8m, a depth of 0.8m, a bottom width of 1.2m and an area of (
) square meters.
⑦ The sum of two right angles of an isosceles triangle is 8.4 decimeters, and its area is (
) Square decimeter.
8 The base of the parallelogram is 9 decimeters, the area is 126 square decimeters, and the height is (
)
Pet-name ruby triangle base length of 8 cm, 6 cm high, equal bottom, equal height parallelogram area is (
) square centimeters.
Attending the isosceles triangle base angle is 40 degrees, then the top angle of this isosceles triangle is (
) degrees.
Second, true or false (16 points)
① An equilateral triangle is an isosceles triangle, and an isosceles triangle is not necessarily an equilateral triangle (
)
② The parallelogram has two heights.
(
)
③ The area of a triangle is always half that of a parallelogram (
)
④ The areas of two triangles with equal base and equal height are equal.
(
)
⑤ Two triangles with equal perimeters have equal areas.
(
)
⑥ Parallelogram is stable.
(
)
⑦ Any triangle must have two acute angles.
(
)
The sum of the internal angles of a triangle is 180 degrees.
(
)
Third, draw the height at the bottom (6 points)
bottom
bottom
bottom
Fourth, find the area below. (Unit: meter) (12 minute)
Five, the application problem (35 points)
(1) triangular billboard, bottom length15m, height 5.4m.. If you want to paint this billboard, you should use 0.7 kilograms of paint per square meter. How many kilograms of paint should you use at least?
(2) Make a pennant with red paper. It is known that the red paper is 1.2m long and 0.8m wide, and the two right angles of the small red flag are 2m and 3m long respectively. How many red flags can a piece of red paper make?
(3) The slope of a plot is 6.4 hectares, and the working width of the seeder is1.8m.. If towed by tractor, it can be 6 kilometers per hour. How many hours does it take to finish planting this land? As shown in the picture, the area of the ladder is 50 square centimeters. What is the area of the shaded part?
○5 The parallelogram wheat field is 300 meters at the bottom and 450 meters high, and the wheat harvest is 189000 kg. How many kilograms of wheat were found per hectare?