Let ABC be a triangle with AB = 3cm, AC = 7cm. The internal bisector of the angle BAC intersects BC at D. The line passing through D and parallel to AC cuts AB at E. Find the measure of DE. Answer: DE = ..........cm.
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Let ABC be a triangle with AB = 3cm, AC = 7cm. The internal bisector of the angle BAC intersects BC at D. The line passing through D and parallel to AC cuts AB at E. Find the measure of DE.
Answer: DE = ..........cm.
Write your answer by fraction in simplest form
ta có:
\(\frac{BD}{DC}=\frac{AB}{AC}=\frac{3}{7}\)( do AD là tia phân giác của \(\widehat{BAC}\))
\(\Rightarrow\frac{BD}{BC}=\frac{3}{11}\)
Ta có:
\(\frac{ED}{AC}=\frac{BD}{BC}=\frac{3}{11}\Rightarrow ED=\frac{3AC}{11}=\frac{3.7}{11}=\frac{21}{11}\)
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Let ABC be an isoceles triangle (AB = AC) and its area is 501cm2. BD is the internal bisector of the angle ABC (D ∈ AC), E is a point on the opposite ray of CA such that CE = CB. I is a point on BC such that CI = 1/2 BI. The line EI meets AB at K, BD meets KC at H. Find the area of the triangle AHC.
bái phục giờ vẫn còn thi toán tiếng anh á ghê á nha
thi xog cấp tỉnh là vứt luôn nhác thi lắm luôn
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Let P be the intersection point of 3 internal bisectrices of a given triangle ABC. The line passing through P and perpendicular to CP intersects AC and BC at M and N. If AP=3cm, BP=4cm, compute AM/BN?
Ta có
\(\widehat{ABM}=\widehat{APC}-\widehat{MPC}=\left(90+\frac{\widehat{ABC}}{2}\right)-90=\widehat{PBC}\)
Tương tự tra có: \(\widehat{NPB}=\widehat{PAM}\)
\(\Rightarrow\Delta MAP\approx\Delta NPB\)
\(\Rightarrow\frac{AP}{PB}=\frac{MA}{NP}=\frac{MP}{NB}\)
\(\Rightarrow MA.NB=NP.MP=NP^2=MP^2\)(Dễ thấy tam giác MNC cân có CP là đường cao và đường phân giác)
Ta lại có: \(\frac{MA}{NB}=\frac{MA^2}{MA.NB}=\frac{MA^2}{NP^2}=\frac{AP^2}{PB^2}=\frac{3^2}{4^2}=\frac{9}{16}\)
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Let ABC be an isoceles triangle (AB = AC) and its area is 501cm2. BD is the internal bisector of the angle ABC (D ∈ AC), E is a point on the opposite ray of CA such that CE = CB. I is a point on BC such that CI = 1/2 BI. The line EI meets AB at K, BD meets KC at H. Find the area of the triangle AHC.
Giúp mình với! Mình sắp thi rồi.
Let ABC be an isoceles triangle (AB = AC) and its area is 501cm2. BD is the internal bisector of the angle ABC (D ∈ AC), E is a point on the opposite ray of CA such that CE = CB. I is a point on BC such that CI = 1/2 BI. The line EI meets AB at K, BD meets KC at H. Find the area of the triangle AHC.
Ghi lời giải dùm mình nha.
Thaks nhiều
with triangle ABC, d is the line passing through B, E of AC. Via E draw straight lines parallel to AB and BC cut d at M, N. D is the intersection of ME and BC. NE lines cut AB and MC at F and K. CMR AFN triangles are in the same form as the MDC triangle
Given a triangle ABC having BAC = 1200, and AC= 2AB. The line passing through A perpendicular to AC intersects the perpendicular bisector of BC at O. Prove that the triangle OBC is an equilateral triangle
Giúp mk vs mk đang cần gấp
câu 1: A rectangle has a length of 60cm and a width of 30cm. It is cut into 2 indentical squares, 2 identical rectangles and a shaded small square. Find the area of the shaded square.
Find the area of the shaded square.
câu 2.The number of ordered pairs (x; y) where x, y ∈ N* such that x2y2 - 2(x + y) is perfect square is ..........
câu 3.Let ABCD be the square with the side length 56cm. If E and F lie on CD, C respectively such that CF 14cm and EAF 45o then CE ........cm.
câu 4.
Given P...
Đọc tiếp
câu 1: A rectangle has a length of 60cm and a width of 30cm. It is cut into 2 indentical squares, 2 identical rectangles and a shaded small square. Find the area of the shaded square.
Find the area of the shaded square.
câu 2.The number of ordered pairs (x; y) where x, y ∈ N* such that x2y2 - 2(x + y) is perfect square is ..........
câu 3.Let ABCD be the square with the side length 56cm. If E and F lie on CD, C respectively such that CF = 14cm and EAF = 45o then CE = ........cm.
câu 4.
Given P(x) = (x2 - 1/2 x - 1/2)1008
If P(x) = a2016x2016 + a2015x2015 + ..... + a1x + a0
then the value of the sum a0 + a2 + a4 + .... + a2014 is ...........
Find the value of P = k(x1) x k(x2) x k(x3) x k(x4) x k(x5) câu 8.The smallest value of
is .............
câu 9.Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm2, 40cm2respectively and M is the midpoint of BD, then the area of the triangle AMD is .........cm2.
câu 10.Bottle A contains 15% syrup. Bottle B contains 40% syrup. When these 2 bottles of syrup are mixed, the syrup content is 30% and the total volume is 600ml. How much syrup is in the bottle A at first?
câu 11.Let ABCD.A'B'C'D' be a cube with AC' = √3cm. Find the total surface area of this cube.
câu 12.Let ABC be a triangle with AB = 3cm, AC = 7cm. The internal bisector of the angle BAC intersects BC at D. The line passing through D and parallel to AC cuts AB at E. Find the measure of DE.
câu 12.Given two numbers x, y such that (4y2 - 12y + 25)(4x2 + 6x + 4) = 28The ratio of y to x is ........ câu 13.Mr.Joseph drives car from A to B at a constant speed. If the speed of the car is increased by 20%, it takes him one hour less than the usual time. If he drives at the constant speed for the first 100km before increasing the speed by 30%, it also takes him one hour less than the usual. The distance of AB is ..........km. câu 14.A triangle ABC has  = 120o and the bisector AD (D ∈ BC). If AB = 40cm, AD = 30cm, then AC = ..... cm. câu 15.As shown in the figure, the length of BE is .............
câu 16.
Let f(x) the polynomial given by f(x) = (1 + 2x + 3x2 + 4x3 + 5x4 + 84x5)
Suppose that f(x) = ao + a1x + a2x2 + ..... + ..... + a50x50.
The value of T = a1 + a2 + .... + a50 is .........
The area of the trapezoid ABCD is .........cm2. câu 18.Find the least possible value of A = 4x2 - 3x + 1/4x + 2015, where x varies in the set of positive real numbers. The least possible value of A is câu 19.
In triangle ABC, BC=AC and BCA=900. D and E are points on AC and AB respectively such that AD=AE and 2CD =BE.Let P be the point of intersection of BD with the bisector of angle CAB. What is the angle PCB in degrees?