1. The top angle of the isosceles triangle is 50 and the bottom angle is (65); The base angle of an isosceles triangle is 40, and the vertex angle of this isosceles triangle is (100).

2. If a rectangle with a length of 18 cm and a width of 12 cm is drawn as a parallelogram with a height of 8 cm, then the area of this parallelogram is (2 16) square cm.

The side of the cylinder is square, the side length is 3 1.4 cm, and the bottom area of this cylinder is (78.5) cm 2.

solve problems

1. A math book is18cm long,15cm wide and 2cm thick. How much paper do you need if you wrap the cover of this math book? If two such math books are packed together, how much wrapping paper do you need at least? The first question: (18 *15+18 * 2+15 * 2) * 2 = 672 (cm2).

Question 2: The two books are 4 cm thick.

( 18 * 15+ 18 * 4+ 15 * 4)* 2 = 804(C㎡)

2. The outer diameter of the bicycle wheel is 60 cm, and it turns 150 turns per minute. How many kilometers does it travel per hour?

3.14 * 60 *150 * 60 =1695600 (km)

3. A cylindrical teacup with a bottom circumference of 25. 12 cm and a height of 10 cm is filled with water and poured into an empty cuboid container with a length of 15.7 cm and a width of 8 cm. How high is the water?

25. 12 * 10 = 25 1.2(C㎡)

251.2/15.7 =16 (cm)

4. A 0.25-hectare triangular wheat field, whose bottom is 125m, and its height is how many meters?

0.25 hectares =2500 square meters

2500/ 125=20 (m)

5. Ventilation duct with square cross section, 2 meters long and side length 1 decimeter. How much space does each ventilation pipe occupy? How many square decimetres of iron sheets are used for each section?

Question 1: 2 meters =20 decimeters.

20* 1* 1=20 (cubic decimeter)

Question 2: 20* 1*4=80 (square decimeter)

Please forgive me for not doing the blank third question. I hope it works for you.