Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
55 views
in Triangles by (71.9k points)
closed by
In a trapezium ABCD, O is the point of intesection of AC and BD, AB||CD and `AB = 2xx CD`. If the area of `triangleAOB= 84cm^(2)` . Find the area of `triangleCOD`.

1 Answer

0 votes
by (72.1k points)
selected by
 
Best answer
In `triangleAOB and triangleCOD`,
`angle1=angle2` (alternate angles)
`angle3= angle4` (alternate angles)
`triangleAOB ~triangleCOD` ( AA corollary)
`(ar(triangleAOB))/(ar(triangleCOD))= (AB^(2))/(CD^(2))`
(ratio of area of two similar triangles is equal to the ratio of square of that corresponding sides)
`((2CD)^(2))/(CD^(2))` ( AB = 2CD, given )
`4/1`
`84/(ar(triangleCOD))=4/1 Rightarrowar(triangleCOD)= 84/4cm^(2)=21cm^(2)`
image

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...