Raise the bottom
Then in the right triangle on the left, the base angle is 30, and the height of the right side he faces is equal to half of the hypotenuse.
The hypotenuse is the waist, and the other right-angled side is that its lower half is 4.
Set height =x
Then x2+4 2 = (2x) 2.
x^2= 16/3
x=4√3/3
So the area =8*(4√3/3)/2= 16√3/3.
2. At △Abc, AB= 17, bc=2 1, CA= 10, find the high AD on the side of BC.
Let CD=x, then BD = 21-X.
So ad 2 = AC 2-CD 2 = AB 2-BD 2.
100-x^2= 17^2-(2 1-x)^2
100-x^2=289-44 1+42x-x^2
x=6
So ad 2 = 100-6 2.
AD=8
In an isosceles triangle, one side is 5 and the other side is 6. Find the height of the bottom.
If it is 556, the height on the bottom edge = radical sign (5 2-3 2) = 4.
If it is 566, the height on the bottom edge = root number (6 2-2.5 2) = root number 1 19/2.
4. It is known that the hypotenuse of a right triangle is17cm, and the length of the right side is 8cm. Try to find the area of this right triangle.
The other right-angled side = root sign (17 2-8 2) = 15.
Area =8* 15/2=60 cm2.
5. The top angle of an isosceles triangle is 120, and the height on the bottom is 20. Try to find out its waist length and bottom length.
Bottom angle =30 degrees, so the height on the bottom edge is half that of the waist.
So waist circumference =20*2=40.
Then half of the cardinal number = radical number (40 2-20 2) =10 radical number 3.
Radix 3 with radix =20
6. In an isosceles right triangle, the length of the right angle is 3, and the length of the hypotenuse is (the root of 3 is 2).
7. In Rt△ABC, if the hypotenuse AB= 1, AB 2+BC 2+CA 2 = 2ab 2 = 2.