Question

Please help ASAP!!!!

Answer 1

to form angle GEC , we join vertex C and E and also , vertex G and E .

so , line EC is the diagonal of the cuboid which is equal to

Diagonal = EC = √ ( l² + b² + h² )

=> EC = √ ( 12² + 3² + 4² )

=> EC = √ ( 144 + 9 + 16 ) = √ ( 169 ) = 13

in triangle , GEC , angle ECG = 90°

and sin ( angle GEC ) = GC / EC

=> sin ( GEC ) = 4 / 13

=> angle GEC = sin-¹ ( 4/13 ) = 17.9°