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.
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
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: \(\frac{MA}{NB}=\frac{MA^2}{MA.NB}=\frac{MA^2}{NP^2}=\frac{AP^2}{PB^2}=\frac{3^2}{4^2}=\frac{9}{16}\)
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
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?
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?
