Can the given lengths be the sides of a right triangle?
7cm, 40cm, 41cm

A right triangle has legnths that have a special relationship to each other
if you have legs legnth a and b and hypotonuse legnth c
a^2+b^2=c^2  yeilds a true statement

so the hypotonuse is normally the longest side so 41 cm is the hypotonuse
c=41

a=7
b=40

subsitute
7^2+40^2=41^2
49+1600=1681
1649=1681
false

this is not a right triangle

Step-by-step explanation:

Assumed Knowledge

Motivation

Content

Radii and chords

Angles in a semicircle

Angles at the centre and circumference

Cyclic quadrilaterals

The alternate segment theorem

Similarity and Circles

Links Forward

Converse of the circle theorems

Coordinate geometry

Calculus

History and Applications

The Euler line

The nine-point circle

Morley’s trisector theorem

Appendix − Converses to the Circle Theorems

Answers to Exercises

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ASSUMED KNOWLEDGE

Introductory plane geometry involving points and lines, parallel lines and transversals, angle sums of triangles and quadrilaterals, and general angle-chasing.

Experience with a logical argument in geometry written as a sequence of steps, each justified by a reason.

Ruler-and-compasses constructions.

The four standard congruence tests and their application to proving properties of and tests for special triangles and quadrilaterals.

The four standard similarity tests and their application.

Trigonometry with triangles.

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MOTIVATION

Most geometry so far has involved triangles and quadrilaterals, which are formed by intervals on lines, and we turn now to the geometry of circles. Lines and circles are the most elementary figures of geometry − a line is the locus of a point moving in a constant direction, and a circle is the locus of a point moving at a constant distance from some fixed point − and all our constructions are done by drawing lines with a straight edge and circles with compasses. Tangents are introduced in this module, and later tangents become the basis of differentiation in calculus.

The theorems of circle geometry are not intuitively obvious to the student, in fact most people are quite surprised by the results when they first see them. They clearly need to be proven carefully, and the cleverness of the methods of proof developed in earlier modules is clearly displayed in this module. The logic becomes more involved − division into cases is often required, and results from different parts of previous geometry modules are often brought together within the one proof. Students traditionally learn a greater respect and appreciation of the methods of mathematics from their study of this imaginative geometric material.

The theoretical importance of circles is reflected in the amazing number and variety of situations in science where circles are used to model physical phenomena. Circles are the first approximation to the orbits of planets and of their moons, to the movement of electrons in an atom, to the motion of a vehicle around a curve in the road, and to the shapes of cyclones and galaxies. Spheres and cylinders are the first approximation of the shape of planets and stars, of the trunks of trees, of an exploding fireball, and of a drop of water, and of manufactured objects such as wires, pipes, ball-bearings, balloons, pies and wheels.