C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch nh\u01b0 th\u1ebf n\u00e0o m\u1edbi \u0111\u00fang chu\u1ea9n l\u00e0 m\u1ed9t trong nh\u1eefng c\u00e2u h\u1ecfi \u0111\u01b0\u1ee3c r\u1ea5t nhi\u1ec1u ng\u01b0\u1eddi quan t\u00e2m. T\u00ednh di\u1ec7n t\u00ednh l\u00e0 m\u1ed9t c\u00f4ng th\u1ee9c v\u00f4 c\u00f9ng quan tr\u1ecdng v\u00e0 c\u1ed1t l\u00f5i \u0111\u1ec3 ch\u00fang ta c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng v\u00e0 gi\u1ea3i c\u00e1c b\u00e0i t\u1eadp m\u1ed9t c\u00e1ch thu\u1eadn ti\u1ec7n nh\u1ea5t. N\u1ebfu nh\u01b0 b\u1ea1n n\u00e0o ch\u01b0a bi\u1ebft th\u00ec h\u00e3y theo d\u00f5i b\u00e0i vi\u1ebft d\u01b0\u1edbi \u0111\u00e2y nh\u00e9.<\/p>\n

T\u1ed5ng h\u1ee3p c\u00e1c c\u00f4ng th\u1ee9c t\u00ednh c\u00e1c h\u00ecnh c\u01a1 b\u1ea3n<\/h2>\n

Di\u1ec7n t\u00edch h\u00ecnh tam gi\u00e1c<\/strong><\/p>\n

T\u00ednh ch\u1ea5t: H\u00ecnh tam gi\u00e1c l\u00e0 h\u00ecnh c\u00f3 3 c\u1ea1nh, 3 g\u00f3c, 3 \u0111\u1ec9nh<\/p>\n

Chi\u1ec1u cao l\u00e0 \u0111o\u1ea1n th\u1eb3ng h\u1ea1 t\u1eeb \u0111\u1ec9nh vu\u00f4ng g\u00f3c v\u1edbi c\u1ea1nh \u0111\u1ed1i di\u1ec7n. K\u00fd hi\u1ec7u \u0111\u00e1y l\u00e0 a chi\u1ec1u cao l\u00e0 h.<\/p>\n

<\/p>\n

C\u00f4ng th\u1ee9c:<\/p>\n

N\u1ebfu nh\u01b0 mu\u1ed1n t\u00ednh di\u1ec7n t\u00ecnh h\u00ecnh tam gi\u00e1c ch\u00fang ta c\u1ea7n ph\u1ea3i l\u1ea5y \u0111\u1ed9 d\u00e0i \u0111\u00e1y nh\u00e2n v\u1edbi chi\u1ec1u cao r\u1ed3i chia cho 2: S= a.h\/2<\/p>\n

T\u00ednh c\u1ea1nh \u0111\u00e1y: L\u1ea5y di\u1ec7n t\u00edch nh\u00e2n v\u1edbi 2 r\u1ed3i chia cho chi\u1ec1u cao.<\/p>\n

T\u00ednh chi\u1ec1u cao: L\u1ea5y di\u1ec7n t\u00edch nh\u00e2n 2 r\u1ed3i chia cho c\u1ea1nh \u0111\u00e1y.<\/p>\n

H = S.2\/a<\/p>\n

C\u00f4ng t\u00ednh di\u1ec7n t\u00edch h\u00ecnh tr\u00f2n<\/strong><\/p>\n

-T\u00ednh ch\u1ea5t: H\u00ecnh tr\u00f2n c\u00f3 c\u00e1c b\u00e1n k\u00ednh b\u1eb1ng nhau<\/p>\n

\u0110\u01b0\u1eddng bao quanh h\u00ecnh tr\u00f2n g\u1ecdi l\u00e0 \u0111\u01b0\u1eddng t\u00f2n<\/p>\n

\u0110i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a t\u00e2m \u0111\u01b0\u1eddng tr\u00f2n th\u00ec g\u1ecdi l\u00e0 t\u00e2m<\/p>\n

\u0110oan th\u1eb3ng n\u1ed1i t\u1eeb t\u00e2m v\u1edbi m\u1ed9t \u0111i\u1ec3m tr\u00ean \u0111\u01b0\u1eddng tr\u00f2ng th\u00ec g\u1ecdi l\u00e0 b\u00e1n k\u00ednh. K\u00fd hi\u1ec7u l\u00e0 r.<\/p>\n

\u0110o\u1ea1n th\u1eb3ng \u0111i qua t\u00e2m n\u1ed1i hai \u0111i\u1ec3m c\u1ee7a \u0111\u01b0\u1eddng tr\u00f2n v\u1edbi nhau th\u00ec g\u1ecdi l\u00e0 \u0111\u01b0\u1eddng k\u00ednh \u0111\u01b0\u1ee3c k\u00fd hi\u1ec7u l\u00e0 d.<\/p>\n

C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch h\u00ecnh tr\u00f2n<\/strong><\/p>\n

Mu\u1ed1n t\u00ednh di\u1ec7n t\u00edch h\u00ecnh tr\u00f2n th\u00ec ch\u00fang ta l\u1ea5y b\u00e1nh k\u00ednh nh\u00e2n v\u1edbi 3, 14<\/p>\n

S= r.r.r.3,14<\/p>\n

Bi\u1ebft di\u1ec7n t\u00edch v\u00e0 mu\u1ed1n t\u00ecm b\u00e1n k\u00ednh ch\u00fang ta l\u00e0m nh\u01b0 sau. L\u1ea5y di\u1ec7n t\u00edch chia cho 3,14 \u0111\u1ec3 t\u00ecm t\u00edch c\u1ee7a hai b\u00e1n k\u00ednh r\u1ed3i t\u00ecm xem s\u1ed1 n\u00e0o nh\u00e2n v\u1edbi ch\u00ednh n\u00f3 b\u1eb1ng t\u00edch \u0111\u00f3 th\u00ec l\u1ea5y b\u00e1n k\u00ednh h\u00ecnh tr\u00f2n.<\/p>\n

V\u00ed d\u1ee5 minh h\u1ecda: Cho di\u1ec7n t\u00edch m\u1ed9t h\u00ecnh tr\u00f2n b\u1eb1ng 28,26 cm^{2 <\/sup>. T\u00ecm b\u00e1n k\u00ednh h\u00ecnh tr\u00f2n \u0111\u00f3.<\/p>\n}

Gi\u1ea3i:<\/p>\n

T\u00edch c\u1ee7a hai b\u00e1n k\u00ednh h\u00ecnh tr\u00f2n l\u00e0:<\/p>\n

28,26 : 3,14 = 9 cm^{2 <\/sup><\/p>\n}

V\u00ec 9 = 3.3 n\u00ean b\u00e1n k\u00ednh h\u00ecnh tr\u00f2n l\u00e0 3 cm<\/p>\n

C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch h\u00ecnh thoi<\/strong><\/p>\n

T\u00ednh ch\u1ea5t: H\u00ecnh thoi l\u00e0 h\u00ecnh c\u00f3 hai c\u1eb7p c\u1ea1nh \u0111\u1ed1i di\u1ec7n song song v\u1edbi b\u1ed1n c\u1ea1nh b\u1eb1ng nhau.<\/p>\n

H\u00ecnh thoi c\u00f3 hai \u0111\u01b0\u1eddng ch\u00e8o vu\u00f4ng g\u00f3c v\u1edbi nhau v\u00e0 c\u1eaft nhau t\u1ea1i trung \u0111i\u1ec3m c\u1ee7a m\u1ed7i \u0111\u01b0\u1eddng. K\u00fd hi\u1ec7u c\u1ee7a hai \u0111\u01b0\u1eddng ch\u00e9o \u1ea5y l\u00e0 m v\u00e0 n<\/p>\n

\u0110\u1ec3 t\u00ednh di\u1ebfn t\u00edch c\u1ee7a h\u00ecnh thoi th\u00ec ch\u00fang ta l\u1ea5y t\u00edch \u0111\u1ed9 d\u00e0i c\u1ee7a hai \u0111\u01b0\u1eddng ch\u00e9o chia cho 2 (c\u00f9ng \u0111\u01a1n v\u1ecb \u0111o):<\/p>\n

C\u00f4ng th\u1ee9c: S= M.x.n\/2<\/p>\n

H\u00ecnh thang<\/strong><\/p>\n

T\u00ednh ch\u1ea5t: H\u00ecnh thang c\u00f3 m\u1ed9t c\u1eb7p c\u1ea1nh \u0111\u1ed1i di\u1ec7n song song v\u1edbi nhau.<\/p>\n

Chi\u1ec1u cao l\u00e0 \u0111o\u1ea1n th\u1eb3ng \u1edf gi\u1eefa hai \u0111\u00e1y vu\u00f4ng g\u00f3c v\u1edbi hai \u0111\u00e1y<\/p>\n

K\u00fd hi\u1ec7u c\u1ee7a \u0111\u00e1y l\u1edbn l\u00e0 a, \u0111\u00e1y nh\u1ecf l\u00e0 b v\u00e0 chi\u1ec1u cao l\u00e0 h<\/p>\n

Di\u1ec7n t\u00edch c\u1ee7a h\u00ecnh thang ta l\u1ea5y t\u1ed5ng \u0111\u1ed9 d\u00e0i 2 \u0111\u00e1y nh\u00e2n v\u1edbi \u0111\u01a1n v\u1ecb \u0111o r\u1ed3i chia cho 2.<\/p>\n

S= (a+b)\/2.h<\/p>\n

C\u00f4ng th\u1ee9c t\u00ednh t\u1ed5ng hai \u0111\u00e1y<\/p>\n

Ta l\u1ea5y di\u1ec7n t\u00edch nh\u00e2n 2 r\u1ed3i chia cho chi\u1ec1u cao.<\/p>\n

(A+b) = s.2:h<\/p>\n

Trung b\u00ecnh c\u1ed9ng c\u1ee7a hai \u0111\u00e1y b\u1eb1ng: a+b\/2<\/p>\n

\u0110\u1ed9 d\u00e0i \u0111\u00e1y l\u1edbn: Ta l\u1ea5y di\u1ec7n t\u00edch nh\u00e2n v\u1edbi hai, chia cho chi\u1ec1u cao r\u1ed3i tr\u1eeb \u0111i \u0111\u1ed9 d\u00e0i \u0111\u00e1y b\u00e9.<\/p>\n

A = S.2:h-b<\/p>\n

\u0110\u1ed9 d\u00e0i \u0111\u00e1y b\u00e9: L\u1ea5y di\u1ec7n t\u00edch nh\u00e2n v\u1edbi 2, chia cho chi\u1ec3u cao r\u1ed3i tr\u1eeb \u0111i \u0111\u1ed9 d\u00e0i c\u1ee7a \u0111\u00e1y l\u1edbn.<\/p>\n

B= s.2:h-b<\/p>\n

T\u00ecnh chi\u1ec1u cao: L\u1ea5y di\u1ec7n t\u00edch nh\u00e2n v\u1edbi 2 r\u1ed3i chia cho t\u1ed5ng \u0111\u1ed9 d\u00e0i hai \u0111\u00e1y<\/p>\n

H = s.2:(a+b)<\/p>\n

Di\u1ec7n t\u00edch h\u00ecnh vu\u00f4ng<\/p>\n

H\u00ecnh vu\u00f4ng l\u00e0 h\u00ecnh t\u1ee9 gi\u00e1c c\u00f3 4 c\u1ea1nh b\u1eb1ng nhau<\/p>\n

Di\u1ec7n t\u00ednh h\u00ecnh vu\u00f4ng s\u1ebd b\u1eb1ng s\u1ed1 \u0111o c\u1ee7a 1 c\u1ea1nh nh\u00e2n v\u1edbi ch\u00ednh n\u00f3.<\/p>\n

S=a.a<\/p>\n

V\u00ed d\u1ee5 minh h\u1ecda: Cho di\u1ec7n t\u00ednh h\u00ecnh vu\u00f4ng l\u00e0 25cm^{2. <\/sup>T\u00ecm c\u1ea1nh c\u1ee7a h\u00ecnh vu\u00f4ng \u0111\u00f3<\/p>\n}

Ta c\u00f3 25= 5.5, v\u1eady c\u1ea1nh h\u00ecnh vu\u00f4ng l\u00e0 5 cm<\/p>\n

H\u00ecnh ch\u1eef nh\u1eadt<\/strong><\/p>\n

T\u00ednh ch\u1ea5t: h\u00ecnh ch\u1eef nh\u1eadt l\u00e0 t\u1ee9 gi\u00e1c c\u00f3 4 g\u00f3c vu\u00f4ng, hai chi\u1ec1u d\u00e0i b\u1eb1ng nhau. K\u00fd hi\u1ec7u chi\u1ec1u d\u00e0i l\u00e0 a, chi\u1ec1u r\u1ed9ng l\u00e0 b<\/p>\n

Mu\u1ed1n t\u00ednh di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt ta l\u1ea5y s\u1ed1 \u0111o chi\u1ec1u d\u00e0i nh\u00e2n v\u1edbi s\u1ed1 \u0111o chi\u1ec1u r\u1ed9ng (c\u00f9ng \u0111\u01a1n v\u1ecb \u0111o)<\/p>\n

S = a.b<\/p>\n

\u0110\u1ec3 t\u00ednh \u0111\u01b0\u1ee3c di\u1ec7n t\u00edch c\u1ee7a c\u00e1c h\u00ecnh c\u01a1 b\u1ea3n tr\u00ean th\u00ec ch\u00fang ta c\u1ea7n ph\u1ea3i n\u1eafm r\u00f5 c\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch c\u1ee7a c\u00e1c h\u00ecnh \u0111\u00f3. Hi v\u1ecdng nh\u1eefng c\u00f4ng th\u1ee9c tr\u00ean s\u1ebd gi\u00fap c\u00e1c b\u1ea1n h\u1ecdc t\u1ed1t h\u01a1n. Ch\u00fac c\u00e1c b\u1ea1n th\u00e0nh c\u00f4ng.<\/p>\n","protected":false},"excerpt":{"rendered":"

C\u00f4ng th\u1ee9c t\u00ednh di\u1ec7n t\u00edch nh\u01b0 th\u1ebf n\u00e0o m\u1edbi \u0111\u00fang chu\u1ea9n l\u00e0 m\u1ed9t trong nh\u1eefng c\u00e2u h\u1ecfi \u0111\u01b0\u1ee3c r\u1ea5t nhi\u1ec1u ng\u01b0\u1eddi quan t\u00e2m. T\u00ednh di\u1ec7n t\u00ednh l\u00e0 m\u1ed9t c\u00f4ng th\u1ee9c… <\/p>\n","protected":false},"author":9,"featured_media":10394,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[415,423],"tags":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts\/10393"}],"collection":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/comments?post=10393"}],"version-history":[{"count":0,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts\/10393\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/media\/10394"}],"wp:attachment":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/media?parent=10393"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/categories?post=10393"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/tags?post=10393"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}