{"id":4465,"date":"2023-01-29T10:00:25","date_gmt":"2023-01-29T04:30:25","guid":{"rendered":"https:\/\/www.aplustopper.com\/?p=4465"},"modified":"2023-01-30T10:03:09","modified_gmt":"2023-01-30T04:33:09","slug":"convex-concave-angle-sum-property-of-quadrilaterals","status":"publish","type":"post","link":"https:\/\/www.aplustopper.com\/convex-concave-angle-sum-property-of-quadrilaterals\/","title":{"rendered":"Convex and Concave Quadrilaterals"},"content":{"rendered":"
Convex quadrilateral:<\/strong> A quadrilateral is called a convex quadrilateral, if the line segment joining any two vertices of the quadrilateral is in the same region. Concave quadrilateral:<\/strong> A quadrilateral is called a concave quadrilateral, if at least one line segment joining the vertices is not a part of the same region of the quadrilateral. The sum of all angles of a quadrilateral is 360\u00b0 or four right angles. Example 1:<\/strong> The angles of a quadrilateral are in the ratio of 1 : 2 : 1 : 2. Find the measure of each angle. Convex and Concave Quadrilaterals Convex quadrilateral: A quadrilateral is called a convex quadrilateral, if the line segment joining any two vertices of the quadrilateral is in the same region. In figure, ABCD is a convex quadrilateral because AB, BC, CD, DA, AC, BD are in the same region of the quadrilateral. In a convex quadrilateral […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[5],"tags":[2492,2491,2489,2490,2483],"yoast_head":"\n
\nIn figure, ABCD is a convex quadrilateral because AB, BC, CD, DA, AC, BD are in the same region of the quadrilateral.
\nIn a convex quadrilateral each angle measures less than 180\u00b0.<\/p>\n
\nThat is, any line segment that joins two interior points goes outside the figure. In a concave quadrilateral at least one angle is a reflex angle, i.e., an angle larger than 180\u00b0.\u00a0In figure, ABCD is a concave quadrilateral because a line joining the vertices A and C is going outside the quadrilateral region.<\/p>\nAngle sum property of a quadrilateral<\/strong><\/h2>\n
\nDraw a quadrilateral ABCD with one of its diagonals AC.
\n
\nDiagonal AC divides the quadrilateral into two triangles, i.e., \u0394ADC and \u0394ABC.
\nClearly \u2220l + \u22202 = \u2220A
\nand \u22203 + \u22204 = \u2220C \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0…(1)
\nWe know that the sum of the angles of a triangle is 180\u00b0.
\n\u2234 In \u0394ABC, \u22201 + \u22203 + \u2220B = 180\u00b0
\nIn \u0394ADC, \u22202 + \u22204 + \u2220D = 180\u00b0
\nSum of the angles of a quadrilateral
\n= Sum of the angles of \u0394ABC and \u0394ADC
\n\u2234 (\u22201 + \u22203 + \u2220B) + (\u22202 + \u22204 + \u2220D)\u00a0= 180\u00b0 + 180\u00b0
\nor \u22201 + \u22203 + \u2220B + \u22202 + \u22204 + \u2220D = 360\u00b0
\nor (\u22201 + \u22202) + \u2220B + (\u22203 + \u22204) + \u2220D = 360\u00b0
\nor \u2220A + \u2220B + \u2220C + \u2220D = 360\u00b0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0(using 1)
\nHence, the sum of the angles of a quadrilateral equals 360\u00b0.<\/p>\n
\nSolution:<\/strong> Let the first angle of a quadrilateral be x.
\nHere, second angle = 2x
\nthird angle = x
\nfourth angle = 2x
\nSum of all angles of a quadrilateral = 360\u00b0
\n\u2234 x + 2x + x + 2x = 360\u00b0
\n6x = 360\u00b0
\nx\u00a0= 60\u00b0
\n\u2234 First angle = x = 60\u00b0
\nSecond angle = 2x = 2 \u00d7\u00a060\u00b0 = 120\u00b0
\nThird angle = x = 60\u00b0
\nFourth angle = 2x = 120\u00b0.<\/p>\n","protected":false},"excerpt":{"rendered":"