Let ABC be a triangle having the ratios of the length of the two side sharing the common vertex A as 2:3 . Let AM be the media and Ak be the angle bisector of the triangle. Find the ratio of the areas of the triangle AKM and the triangle AKB.
Let ABC be a triangle having the ratios of the length of the two side sharing the common vertex A as 2:3 . Let AM be the media and Ak be the angle bisector of the triangle. Find the ratio of the areas of the triangle AKM and the triangle AKB.
( Giải bằng tiếng anh )
On the supposition that AB<AC
AK be the angle bisector of the triangle
\(\Rightarrow\) \(\frac{KB}{KC}=\frac{AB}{AC}=\frac{2}{3}\)
\(\Rightarrow\frac{MB-MK}{MC+MK}=\frac{MC-MK}{MC+MK}=\frac{2}{3}\)
\(\Rightarrow3MC-3MK=2MC+2MK\)
\(\Rightarrow MC=5MK\)
\(\Rightarrow BK=MC-MK=5MK-MK=4MK\)
Let AH be the height of the triangle
\(\Rightarrow\frac{S_{AKM}}{S_{ABK}}=\frac{\frac{AH.KM}{2}}{\frac{BK.AH}{2}}=\frac{KM}{4KM}=\frac{1}{4}\)
If AB > AC then
\(\Rightarrow CM=5MK\)
\(\Rightarrow Bk=CM+MK=5MK+MK=6MK\)
\(\Rightarrow\frac{S_{AKM}}{S_{AKB}}=\frac{\frac{AH.MK}{2}}{\frac{AH.BK}{2}}=\frac{MK}{6MK}=\frac{1}{6}\)
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 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:
\(\frac{ED}{AC}=\frac{BD}{BC}=\frac{3}{11}\Rightarrow ED=\frac{3AC}{11}=\frac{3.7}{11}=\frac{21}{11}\)
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
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.
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.
đựng đường cao 2 bên áp dụng 2 tam giác đồng dạng suy ra tỉ số diện tích
đáp án 22 cm2