triangles introduction

Area of a region, bounded by a geometrical figure measures the portion of the plane occupied by the region. When we talk of the area of D ABC, we mean the area of the region bounded by D ABC. We shall discuss the geometrical aspects of areas of some important figures like triangles, paral..

When calculating sides or angles of right angled triangles, it is easiest to use the appropriate trigonometric relation. Finding the value of trigonometric ratios from the tables is learnt easily. Nowadays of course calculators are able to give accurate values for any degree of tan, sin o..

Recall that if two straight lines are not parallel, they meet at a point when produced. Observe lines l and m which meet at a point (O). In the diagram, l and m are called intersecting lines. O is called the point of intersection. Similarly two line segments or two rays may intersect at a point. Th..

Let us recapitulate the trigonometric ratios (t-ratios). There are six t-ratios. D ABC is a right-angled triangle, B = 90 o . (i) In short, (ii) In shor..

Introduction - In the given triangle ABC, A = 90 o . Squares BCDE, ABFG and ACKL are drawn on the sides of the triangle. area of square BCDE = BC 2 area of square ABFG = AB 2 area of square ACKL = AC 2 Pythagoras' theorem states that, area of square BCDE = area of squa..

Introduction - Triangles are classified on the basis of the lengths of their sides as scalene, isosceles, or equilateral triangles. When any two sides of a triangle are equal it is called as an "isosceles triangle". The unequal side is called its ba..

Introduction - We can prove some more properties of triangles using the properties of parallelograms seen in the previous chapter. We find that the line segment joining the mid points of any two sides of the triangle is parallel to the third side and is equal to half o..

Introduction - Area of a region, bounded by a geometrical figure measures the portion of the plane occupied by the region. When we talk of the area of D ABC, we mean the area of the region bounded by D ABC. We shall discuss the geometrical aspects of areas of some important figures like h..

Introduction - Let us recapitulate the trigonometric ratios (t-ratios). There are six t-ratios. D ABC is a right-angled triangle, B = 90 o . (i) In short, (ii) In shor..

Introduction - Geometry originated when man felt the need to measure his land. Ancient Egyptians were perhaps the first people to study geometry. Later, the Babylonians studied in a systematic wa..