☰ Contents · Geometry

SSS criterion. Perpendicular bisector

Lessons 25–26 · 2 lessons · Geometry Grade 7, corrected and expanded 3rd edition. Yangiyo‘l Poligraf Servis, Tashkent, 2017 (approved by the Ministry of Public Education)
Answers are for parents and teachers.
1
△ABC = △MNK by SSS, ∠C = 38°. Find ∠K (degrees).
2
D lies on the perpendicular bisector of AB, DA = 7.5 cm. Find DB.
3
In △ABC, AC = 21, E lies on AC with EB = EC. If AE = 8, find EB.
4
Explain in your own words why a triangle is rigid and a quadrilateral is not.
5
A wooden frame is needed. How many diagonal braces are enough to make a quadrilateral rigid?