Question

is this scalene triangle whose measure 70°,80° and 90 °. why ? give reason​

Answer 1

Answer:

(i) A triangle has at least ………… acute angles.

(ii) A triangle cannot have more than ……… right angle.

(iii) A triangle cannot have more than ………… obtuse angle.

(iv) In every triangle, the sum of (interior) angles of a triangle = ……….. right angles.

(v) In every triangle, an exterior angle + adjacent interior angle = ………… degrees.

(vi) In every triangle, an exterior angle = sum of the …….. interior opposite angles.

(vii) In a right-angled triangle, if one of the acute angles measures 25° then the measure of the other acute angle is …………

Solution:

(i) A triangle has at least two acute angles.

(ii) A triangle cannot have more than one right angle.

(iii) A triangle cannot have more than one obtuse angle.

(iv) In every triangle, the sum of (interior) angles of a triangle = two right angles.

(v) In every triangle, an exterior angle + adjacent interior angle = 180° degrees.

(vi) In every triangle, an exterior angle = sum of the two interior opposite angles.

(vii) In a right-angled triangle, if one of the acute angles measures 25°

then the measure of the other acute angle is 65°.