Year 10 Interactive Maths - Second Edition | | | Congruent figures have the same size and the same shape. The corresponding sides and angles of congruent figures are equal. Square ABCD is congruent to square EFGH as their corresponding sides and angles are equal. Note: Congruent figures are exact duplicates of each other. One could be fitted over the other so that their corresponding parts coincide. The concept of congruence applies to figures of any type. In this section we will consider congruent triangles, principles of congruent triangles and their applications.
Congruent Triangles
Congruent triangles have the same size and the same shape. The corresponding sides and the corresponding angles of congruent triangles are equal. Note:
Principles of Congruent Triangles
The following principles of congruence are used depending on the information given. 1. The side-side-side (SSS) principle Two triangles are congruent if corresponding sides are equal. 2. The side-angle-side (SAS) principle Two triangles are congruent if two pairs of corresponding sides and the angle included between the sides are equal. 3. The angle-side-angle (ASA) principle Two triangles are congruent if two pairs of corresponding angles and a pair of corresponding sides are equal. 4. The right angle-hypotenuse-side (RHS) principle Two right-angled triangles are congruent if the hypotenuses and one pair of corresponding sides are equal. | |
In order to continue enjoying our site, we ask that you confirm your identity as a human. Thank you very much for your cooperation.
Melissa T.
asked • 05/13/18
It's a rectangles and has 4 sides and one is 60 degrees
1 Expert Answer
Kenneth S. answered • 05/13/18
Expert Help in Algebra/Trig/(Pre)calculus to Guarantee Success in 2018
Poorly written question. If it's a rectangle, there's no need to count its sides.
If the rectangle is ABCD and DC = 10, then angle ABD can be determined if we know AD or some specific acute angle's measurement.
ASSUMING that angle ADB measures 60 degrees, then angle ABD would measure thirty degrees, and side AD would measure 10/√3, by the way.
$\begingroup$
Beth draws $5$ points $A$, $B$, $C$, $D$, $E$ on a circle as well as the tangent to the circle at $A$, such that all angles marked with $x$ are equal.
What is the angle of $ABD$?
$\endgroup$ 2